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NOTA BENE:
Vortices
An extensive theoretical study of the effect of critical fluctuations on the B-T phase diagram in clean, extreme type-II superconductors (kappa >> 1) in zero and finite magnetic fields has been carried out by A. K. Nguyen (Trondheim) and A. Sudbo (Trondheim and Caltech). In zero field, the authors show that the superconducting to normal-metal transition is described by the unbinding of thermally induced vortex loops. In other words, superconductivity is destroyed by fluctuations in the phase of the order parameter; amplitude fluctuations are far from critical at Tc. The authors also find that as Tc is approached from below, the vortex line tension epsilon(T) vanishes as a power law, epsilon(T) proportional to |T-Tc |^[gamma], where gamma = 1.45+-0.05, and there is a diverging length in the problem, L_0(T) --> infinity as T --> Tc^^[-]. The authors also relate these results to the dual field phi, and in conjunction with the Fisher scaling law gamma = nu(2-eta_[phi]) the authors extract the value eta_[phi] = -0.18+-0.07.
In finite field, Nguyen and Sudbo find that the vortex-line lattice
melts in a first-order phase transition along the line T_m(B) into a
completely incoherent vortex liquid characterized by zero global phase
coherence in all directions. The authors find a crossover from mean-
field scaling at high fields to 3D XY scaling at low fields. In
addition, the authors find that a change in the vortex-tangle
connectivity O_L signals the presence of another transition line T_L(B),
which lies above the melting line. T_L(B) is the finite-field extension
of the zero-field vortex-loop unbinding point, and thus has an endpoint
at the zero-field critical temperature, T_L(0) = Tc. Below T_L,
connectivity of the vortex system is determined exclusively by the
field-induced vortex lines, but above T_L, there exist thermally
generated vortex lines that thread across the entire system
perpendicular to the magnetic field. The authors find that the vortex
system in the clean limit exhibits three distinct phases in the B-T
phase diagram, characterized by the average values of the Ginzburg-
Landau order parameter
The resistivity of clean YBa2Cu3O7-d (Y-123 or YBCO) in the vortex-
liquid state has been measured by S. N. Gordeev (Southampton) et al.
Using scaling analysis, the authors find two distinct regimes. While at
high temperatures the vortex liquid is unpinned and the resistivity
assumes its free-flux-flow state, at lower temperatures the vortex
dynamics can be described in terms of the model of a very viscous
liquid, in which the vortex motion is controlled by thermally activated
processes with high energy barriers U_[pl] >> k_BT. The authors found
that the ratio of the activation energy to the melting temperature has a
constant value U_[pl](T_m )/k_BT_m ~~ 12, independent of the degree of
underlying disorder. This is in agreement with recent theoretical
predictions for vortex-line-cutting energies and implies that the vortex
liquid is highly entangled.
Measurements of the nonlinear susceptibility of YBa2Cu4O8 (Y-124),
Bi2Sr2CaCu2O8+d (Bi-2212), and untwinned YBa2Cu3O7-d (Y-123) crystals
near the superconducting critical temperature Tc have been carried out
by F. Mrowka (Leipzig) et al. to determine the lower critical field
H_[c1](T). The ac-field-amplitude dependence of the susceptibility for
homogeneous Y-124 and Bi-2212 crystals is in agreement with the
geometrical-barrier model, allowing the authors to determine the
penetration field H_p(T) proportional to H_[c1](T). The authors also
found that the previously reported breakdown of H_[c1] near Tc coincides
with the low-temperature ac-field-independent onset of the
superconducting transition and that this anomalous behavior of H_[c1](T)
is not an intrinsic property but rather is due to the influence of
inhomogeneities.
A preprint by S. Okayasu and H. Asaoka (JAERI) reports the experimental
observation of a new vortex phase in a detwinned YBCO single crystal.
Using dc magnetization (M vs H) hysteresis measurements at fixed
temperatures above 55 K but below the vortex-lattice melting line
T_m(B), the authors found an apparently reversible region (region IV)
between the irreversibility line B_[irr](T) and a reentrance line
B_[on2p](T), which marks the onset of a second peak in the magnetization
hysteresis. While the irreversibility line B_[irr](T) decreases with
increasing temperature, the authors found that the reentrance line
B_[on2p](T) increases with temperature. Using ac susceptibility
measurements, the authors found the magnitude of the third-harmonic
signals to be large only in region IV between the irreversibility line
and the reentrance line.
A method based on partial magnetization loops has been used by S.
Kokkaliaris (Southampton) et al. to study memory effects in detwinned
YBa2Cu3O7-d single crystals. The measurements have revealed the
transition from a dislocation-free Bragg glass to a disordered vortex
phase. On the B-T phase diagram, this transition occurs along a
boundary that is close to the onset of the second magnetization peak.
For fields above the transition line, metastable topological disorder
invades the vortex system, leading to a pronounced dependence of the
critical current on the formation history of the vortex lattice.
The quasiparticle density of states in d-wave superconductors containing
a vortex lattice has been calculated by K. Yasui and T. Kita (Hokkaido),
who self-consistently solved the Bogoliubov-de Gennes equations. For a
pure d_[x^2-y^2] state, the authors found that (a) low-energy
quasiparticle bands in the magnetic Brillouin zone have large dispersion
even in low magnetic fields, indicating the absence of bound states for
an isolated vortex, and (b) in finite fields with small k_Fxi_0, the
calculated tunneling conductance at the vortex core shows a double-peak
structure near zero bias, qualitatively consistent with the STM
experiment by I. Maggio-Aprile et al., Phys. Rev. Lett. 75, 1754 (1995).
The authors also found that mixing of a d_[xy]- or an s-wave component,
if any, develops gradually without transitions as the field is
increased, having little effect on the tunneling spectra.
Using London theory, E. Sardella (Bauru) et al. have calculated the
reversible magnetization curve of a superconducting (kappa = 100) film
of width a = 7[lambda] and thickness b < lambda in a parallel magnetic
field. Multiple peaks in M(H) occur, corresponding to different numbers
N of vortices in the film (N <= 30). For b = 0.5 lambda, the Gibbs free
energy minimum corresponds to only a single row of vortices along the
midline of the film, while for b = 0.75 lambda, there are two staggered
rows of vortices straddling the midline.
The nucleation of superconductivity in a uniform perpendicular magnetic
field H in Al 2.0 micrometers x 2.0 micrometers microsquares containing
two or four submicron holes (antidots) has been studied experimentally
and theoretically by V. Bruyndoncx et al. (Leuven). In low magnetic
fields, the normal-superconducting phase boundary shows oscillations in
Tc(H) arising from fluxoid quantization around each antidot, similar to
the behavior in a network. In high magnetic fields, the Tc(H)
boundaries of the perforated microsquare and a reference nonperforated
microsquare have cusps at the same values of Phi/phi_0 (Phi = applied
flux threading the total square area, phi_0 = superconducting flux
quantum), while the background on Tc(H) becomes quasilinear, indicating
that a giant vortex state is established.
RBa2Cu3O7-d
The flux-pinning behavior of ternary melt-processed (Nd-Eu-Gd)Ba2Cu3O7-d
[(NEG)-123] superconductors with varying defect concentrations has been
studied by A. K. Pradhan et al. (SRL-ISTEC). The authors interpret the
maximum in Jc(B) at 2-3 T in terms of pinning-induced vortex
entanglement in the vortex-liquid phase.
As noted in a preprint by I. M. Fita (Donetsk) et al., it has been found
that pressure-induced superconductivity (Tc --> 30 K) can occur in
normally nonsuperconducting NdBa2Cu3O6.67 (Nd-123). The authors have
found that when the pressure is released, oxygen disordering gradually
occurs. Over a few hours, the unit-cell volume V_[cell] increases with
time, the hole density decreases, and Tc decreases to zero. Oxygen
disordering upon pressure release was found to occur five times faster
than oxygen ordering under pressure.
Bi Cuprates
A preprint by R. S. Gonnelli (Torino) et al. reports solutions of the
real-axis d-wave Eliashberg equations for Bi2Sr2CaCu2O8+d (Bi-2212) to
satisfactorily fit break-junction tunneling experiments, and an
alpha^2F(omega) was obtained. However, the same procedure was unable to
fit the differential conductance curves from recent STM experiments.
Three preprints listed in this issue report enhancements of the critical
current density Jc in Bi-2212 samples grown in a high magnetic field.
H. B. Liu et al. (MIT) report experiments on Bi-2212 films of thickness
25-125 micrometers melt-grown in fields up to 10 T; H. B. Liu (MIT) et
al. report results for Bi-2212/Ag tapes melt-grown in magnetic fields up
to 10 T; and S. Pavard et al. (Grenoble) report on Jc enhancements in
bulk Bi-2212 superconductors with MgO additions, where the samples were
hot-forged in a magnetic field of 5.7 T.
Nondestructive measurements by P. Usak (Bratislava) have been used to
determine the transport current distribution across the width of a
superconducting wire-in-tube (WIT) (Bi,Pb)-2223/Ag tape. The author
measured the spatial dependence of the magnetic self-field just above
the tape and used the Biot-Savart law to invert the results and obtain
the current distribution. The measurements showed that at the critical
current, the current capacity in the central section was higher than at
the edges of the tape.
Measurements of the ac susceptibility of a well-textured (Bi,Pb)-2223/Ag
tape have been carried out by G. C. Han and C. K. Ong (Singapore) as a
function of temperature, externally applied dc magnetic field, and angle
theta between the field and the tape plane. The authors found that the
results could be scaled using the three-dimensional anisotropic
effective-mass model, but with a gamma ~ 4 most likely reflecting the
misalignment of the grains, rather than indicating the anisotropy of
perfectly aligned Bi-2223.
Other Cuprates
The mixed-state Hall resistivity rho_[xy] and the longitudinal
resistivity rho_[xx] in HgBa2CaCu2O6+d (Hg-1212), HgBa2Ca2Cu3O8+d (Hg-
1223), and Tl2Ba2CaCu2O8+d (Tl-2212) thin films have been investigated
by W. N. Kang (POSTECH) as functions of the magnetic field H up to 18 T.
The scaling exponent beta in rho_[xy] = A rho_[xx]^[beta] was found to
be 1.9+-0.1 in the clean limit at high H and low temperature T. In the
moderately clean limit at low H and high T, beta = 1.0+-0.1, consistent
with a theory based on midgap states in the vortex core.
Infrared studies of the c-axis electrodynamics of Tl2Ba2CuO6+d (Tl-2201)
crystals have been carried out by A. S. Katz (US-San Diego) et al. A
sum-rule analysis reveals spectral weight shifts that can be interpreted
as a kinetic-energy change at the superconducting transition. In
optimally doped crystals showing an incoherent normal-state response,
the kinetic energy is lowered at T < Tc, but no significant change is
found in overdoped samples, which have more coherent conductivity at T >
Tc.
As reported by S. Yu et al. (NIRIM), critical current densities Jc and
irreversibility fields B_[irr] of the high-Tc superconductors
(Cu,Cr)Sr2Can-1CunO2n+3 [(Cu,Cr)-12(n-1)n, n = 2 (Tc = 81 K) and n = 3
(Tc = 103 K)] prepared under high pressure have been determined from dc
magnetization hysteresis. Plotted as a function of T/Tc, the values of
Jc(B=0) and Jc(B=1T) are higher than those of other high-Tc
superconductors, including YBa2Cu3O7-d, for almost the entire range of
temperatures. The B_[irr] values are also very high; at 77 K, for
example, B_[irr] > 5 T for (Cu,Cr)-1223. The authors suggest that the
good Jc properties of (Cu,Cr)-1212 and (Cu,Cr)-1223 are caused by their
less anisotropic electronic structures and high density of pinning
centers due to random arrangement of Cu and Cr in the blocking layer.
Films
The influence of a driving force and vortex-lattice motion on the
vortex-depinning and dissipation in vibrating YBa2Cu3O7-d
superconducting films has been investigated by A. V. Pan et al.
(Leipzig). The authors observed a motional narrowing of the depinning
transition.
Thermomagnetic instabilities (flux jumps or vortex avalanches) have been
observed by P. Esquinazi (Leipzig) et al. in Nb thin films. The field
H_[SMP](T) at the second magnetization peak separates the region of flux
jumps, H < H_[SMP](T), from smooth behavior at H > H_[SMP](T). Using
local magnetization measurements, the authors also found dome-like flux
profiles at low fields.
A preprint by X. Cui et al. (Oak Ridge) reports that a reel-to-reel
electron-beam-evaporation system has been developed to continuously
deposit epitaxial CeO2 and other oxide buffer layers on meter-long
lengths of rolled Ni tapes. Jcs as high as 5 x 10^5 A/cm^2 at 77 K in
self-field have been achieved for YBCO films deposited on short segments
of these substrates.
According to a preprint by F. Zygalsky et al. (TU-Berlin), it is
possible to produce high-Tc thin films from polymer metal precursors by
a simple spin-coating technique. The authors show how this method can
be used to manufacture YBa2Cu3O7-d (Y-123) and (Bi,Pb)2Sr2Ca2Cu3O10+d
[(Bi,Pb)-2223] thin films and to produce microbridges without etching
using photolithography on the precursor film.
Large-area crack-free thick YBa2Cu3O7-d films have been prepared by R.
Woerdenweber (Juelich) et al. on CeO2-buffered r-cut sapphire (two-inch
diameter) with thickness up to 700 nm, smooth surfaces (peak-to-valley
roughness less than 10 nm), high critical currents (Jc > 2 MA/cm^2 at 77
K and 0 T), and low microwave surface resistance [R_s(77K) = 1.4
milliohms and R_s(4.2K) ~~ 110 milliohms at 19 GHz], comparable with the
best values reported for YBCO films on structurally better-matched
substrates.
Low-power nonlinear effects in high-temperature superconducting
microwave devices have been studied by J. C. Booth et al. (NIST-
Boulder), who measured third-harmonic generation at 76 K in coplanar
waveguide transmission lines of different geometries fabricated from
YBCO thin films with Jc(76K,0T) = 3.0 x 10^6 A/cm^2. The authors were
able to analyze their results using a simple transmission-line model
with a nonlinear inductance arising from a current-dependent
superconducting penetration depth, characterized by a scaling current
density J_0 = 3.0 x 10^7 A/cm^2 at 76 K.
A related preprint by J. H. Claassen (NRL) et al. describes another
method to determine the dependence of the penetration depth lambda(J) on
the current density J. The technique involves a pair of small coaxial
coils positioned on opposite sides of the film. Using this method and
the model lambda^2(T,J) = lambda^2(T,0)[1+(J/J_0)^2], the author
obtained values of J_0 in good agreement with those measured by third-
harmonic generation in coplanar waveguide transmission lines at 5 GHz.
This nondestructive technique could be used to screen films before
incorporating them into circuits sensitive to nonlinear effects.
Applications
Contained in this issue are a number of preprints from Forschungszentrum
Juelich related to applications of high-temperature superconducting
YBa2Cu3O7-d rf SQUIDs and gradiometers. P. Selders et al. (Juelich)
report that the low-frequency 1/f noise can be strongly reduced when the
vortex lattice in the body of a SQUID is geometrically matched to an
antidot (hole) lattice. Y. Zhang et al. (Juelich) reports on the
performance of a planar multiturn flux transformer integrated with a
superconducting labyrinth resonator serving as the planar tank circuit
for an rf SQUID magnetometer. H. R. Yi et al. (Juelich) report
numerical calculations of the coupling coefficient k^2 between a
superconducting coplanar resonator and a flip-chip-coupled washer rf
SQUID. M. Bick (Juelich) et al. report on a highly sensitive rf SQUID
vector (x,y,z) magnetometer system which operates at 77 K and is
suitable for electromagnetic geophysical exploration. D. F. He et al.
(Juelich) report on the magnetically unshielded operation of a device
consisting of three magnetometer SQUIDs oriented in the x, y, and z
directions. R. Hohmann et al. (Juelich) report on the development of an
automated inspection system using an HTS SQUID gradiometer sensor for
eddy-current detection of deep-lying flaws in large aircraft wheels. Y.
Tavrin (Juelich) et al. report on the development of a highly sensitive
second-order gradiometer using three HTS SQUIDs as magnetic sensors for
nondestructive testing of small ferrous inclusions in aircraft engine
disks.
A preprint by Y. Zhang (Juelich) et al. reports the development of a
radio-frequency bias-current scheme with reversal frequency up to 50 MHz
for dc SQUIDs. The SQUID and the readout electronics were connected via
a quarter-wavelength transmission line, which also served as the
resonant matching circuit.
Two more papers from Juelich describe the performance of high-Tc
Josephson mixers. O. Harnack (Juelich) et al. report on experimental
studies of noise properties and conversion efficiency of YBCO Josephson
mixers and hot-electron-bolometric (HEB) mixers at frequencies between
90 GHz and 550 GHz. S. Beuven et al. (Juelich) report on the
experimental realization of a sub-mm wavelength oscillator based on YBCO
Josephson junctions integrated on-chip with a detector Josephson-
junction mixer. The oscillator was a 2D array of 20 step-edge junctions
biased in parallel, such that all junctions of the network were
oscillating with the same frequency.
The design and fabrication of a low-noise HTS magnetometer consisting of
a low-inductance (<16 pH) YBCO dc SQUID coupled to a 28 nH YBCO pickup
loop flux transformer fabricated on the same 1 cm^2 substrate is
described by N. J. Exon et al. (DERA-Malvern). Efficient coupling was
achieved by using a flip-chip intermediate flux transformer, resulting
in a magnetometer with a high sensitivity per unit area. The measured
white noise, which was higher than the design value, was due largely to
Johnson noise from the PrBa2Cu3O7-d in the flux-transformer crossovers.
A method for the determination of the critical current density Jc from
measurements of the levitation force on a permanent magnet is described
in a paper by A. A. Kordyuk (Kiev) et al. The calculated first and
second levitation-force hysteresis loops calculated with these Jc values
are in good agreement with experimental data on melt-processed YBCO
samples.
Theory
A preprint by L. P. Pryadko (Princeton) et al. analyzes the properties
of a general Ginzburg-Landau free energy with competing order
parameters, long-range interactions, and global constraints (e.g., a
fixed value of total charge) to address the physics of stripe phases in
underdoped high-Tc and related materials. For a local free energy
limited to quadratic terms of the gradient expansion, only uniform or
phase-separated configurations are found to be thermodynamically stable.
Stripe or other nonuniform phases can be stabilized by long-range
forces, but they can have nontopological (in-phase) domain walls only
where the components of the antiferromagnetic order parameter never
change sign, and the periods of charge and spin density waves coincide.
The authors discuss the implications for the phase diagram of underdoped
cuprates.
Considering both large-U and small-U orbitals, J. Ashkenazi (Miami)
finds that the high-Tc cuprates are characterized by a striped structure
and three types of carriers: polaron-like stripons carrying charge,
quasielectrons carrying charge and spin, and svivons carrying spin and
lattice distortion. The author shows that this electronic structure
leads to the anomalous physical properties of the cuprates, and
specifically the systematic behavior of the resistivity, Hall constant,
and thermoelectric power. In this theory, high-Tc pairing results from
transitions between pair states of quasielectrons and stripons through
the exchange of svivons. A pseudogap phase occurs when pairing takes
place above the temperature where stripons become coherent, and this
temperature determines the Uemura limit.
As noted in a preprint by B. Normand (Basel) et al., LaCuO2.5 is a
system of coupled two-chain cuprate spin ladders, which may be doped
systematically by Sr substitution. Motivated by the recent synthesis of
single crystals, the authors used a model of spin-fluctuation-mediated
superconductivity, where the pairing potential is strongly peaked at pi
in the ladder direction, to investigate the possibility of
superconductivity in this compound. The authors solved the coupled gap
equations on the bonding and antibonding ladder bands to find
superconducting solutions across the range of doping. They predict that
sufficiently clean single crystals of La0.9Sr0.1CuO2.5 should be
superconducting with a transition temperature around 25 K.
A preprint by G. A. Ummarino and R. S. Gonnelli (Torino) considers
consequences of the breakdown of Migdal's theory in high-Tc
superconductors. They find that the experimental coupling constant
lambda, gap parameter Delta, and transition temperature Tc are all
enhanced, and that the enhancement is greater for Delta than for Tc,
leading to an increased value of the experimental ratio 2[Delta]/k_BTc.
The authors conclude that the renormalized values of lambda and
2[Delta]/k_BTc are compatible with a conventional strong-coupling
electron-boson origin of superconductivity.
The effect of impurity scattering in superconductors usually has been
calculated theoretically assuming s-wave impurity scattering, which
leads to results depending only upon the mean free path and the impurity
cross section. M. L. Kulic (Bayreuth) and O. V. Dolgov (Tuebingen) have
investigated corrections coming from anisotropy in the scattering cross
section. They find both quantitative and qualitative deviations from
the s-wave isotropic pair-breaking theory in the transition temperature,
density of states, quasiparticle bound states at impurities, and pinning
of vortices by impurities.
Using a multi-Josephson-junction model, S. Sakamoto (Seikei) et al. have
investigated voltage-biased I-V characteristics of high-Tc
superconductors. The I-V characteristics show a complicated behavior
due to interlayer couplings among the superconducting phase differences
mediated by the charging effect.
In analyzing the current-voltage characteristics of polycrystalline
RBa2Cu3O7-d (R = Y or Gd) samples, M. Prester (Zagreb) concludes that
the current-carrying medium is an object of fractal geometry.
Overviews
As noted in a review by A. Gilabert (Nice) et al., persistent
photoconductivity is an unusual property of the high-temperature
superconductors. Illumination of these compounds can lead to a change
in doping that persists at low temperatures but relaxes back to its
initial value at elevated temperatures. Photoinduced effects also can
be used to probe or modify the properties of grain boundaries in grain-
boundary Josephson junctions. The authors review the experimental data
and the proposed models for persistent photoconductivity (128 refs.).
In-situ high-temperature optical microscopic observations of the
nucleation, growth, and morphology of RBa2Cu3O7-d (R-123, R = Nd,Y) are
reviewed in a book chapter by D. K. Aswal (Shizuoka) et al. By
observing the crystallization of Nd-123 from high-temperature solutions,
the authors found that the growth mechanism changes from 3D growth, via
2D layer-by-layer growth, to continuous dendritic growth with increasing
supersaturation, suggesting that interface kinetics is the rate-limiting
factor (111 refs.).
A review by J. F. Annett (Bristol) summarizes the evidence for or
against conventional s-wave and unconventional p-wave or d-wave pairing
in various anomalous superconductors including the cuprates, ruthenates,
organics, borocarbides, bismuthates, fullerenes, and C15s. The author
notes that there is now strong evidence for p-wave pairing in Sr2RuO4
(104 refs.).
An overview on the deposition of high-Tc superconducting thin films has
been prepared by R. Woerdenweber (Juelich). The author discusses and
compares the major technologies, and describes the advantages and
disadvantages of various substrate materials. Film nucleation, growth
modes, and the consequences of lattice mismatch also are discussed (90
refs.).
The physics of Raman spectroscopy and its application to study phonons,
interband and intraband electronic excitations, the electron-phonon
interaction, and crystal-field transitions between f-electron levels in
high-Tc superconductors are the subject of a review by M. Cardona (MPI-
Stuttgart). The author notes that Raman experiments reveal a remarkably
large electron-phonon interaction in HgBa2Ca3Cu4O10+d (Hg-1234, Tc = 123
K) (81 refs.).
A review by J. R. Hull (Argonne) discusses the use of melt-textured bulk
high-temperature superconductors in magnetic-levitation applications.
The author discusses the behavior of the levitation force, stiffness,
damping, and rotational losses. These materials are finding uses in
superconducting bearings, flywheel energy storage, and other levitation
applications (77 refs.).
The superconducting properties of quasi-two-dimensional organic metals
have been reviewed by J. Wosnitza (Karlsruhe). The author also presents
recent experimental results on the magnetic phase diagram, fluctuation
effects, vortex dynamics, and specific heat. There is still no general
consensus on the nature of the superconducting state in organic
materials (52 refs.).
An overview of selected properties of quaternary intermetallic rare-
earth transition metal borocarbides and related boronitride compounds
has been prepared by S.-L. Drechsler (Dresden) et al. The authors also
discuss theoretical calculations, the mechanism of superconductivity,
and the interplay of superconductivity and magnetism for compounds with
pure and mixed rare-earth components (47 refs.).
The fabrication of high-Tc superconducting Josephson-junction arrays and
their application as voltage standards, microwave radiation sources, and
mixers are discussed in a review by M. Darula (Juelich) (41 refs.).
A review of how neutron scattering can be used to search for mechanisms
of superconductivity has been prepared by G. Aeppli (Riso and NEC-
Princeton) et al. The authors report results from UPt3, La2-
x(Sr,Ba)xCuO4, and YBa2Cu3O6.67 (36 refs.).
A review by P. Woelfle (Karlsruhe) examines the properties of superfluid
[3]^He as a well-studied model of unconventional superfluidity, and
includes a discussion of BCS theory extended to spin-triplet p-wave
states, the nodal structure of the energy spectrum, and its implications
for thermodynamic and transport properties. The author also considers
charged superfluids (i.e., superconductors) and their coupling to the
electromagnetic field (33 refs.).
Contributed by John R. Clem
Contents: Technology News begins on page 6; Preprints begin on page 7;
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TECHNOLOGY NEWS
(Also see Applications section of Nota Bene.)
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about your corporation or laboratory) to the editor.
A four-year cooperation agreement was signed recently by Pirelli Cables
and Systems, ENEL, and Edison for the development, production, and
testing of a high-temperature superconducting cable system. The
objective of this partnership is to conduct a study to assess the
commercial use of new systems based on this technology in existing
electricity transmission networks, and to evaluate the impact and
benefits on those networks. The development program will include the
first field trial of an industrialized HTS cable system in Italy.
Pirelli Cables and Systems, ENEL, and Edison, which have extensive
experience in the field of superconductivity research, will combine
their respective capabilities to develop a 132 kV 3-phase HTS cable
system capable of transporting 3,000 A current continuously, more than
double the load of a conventional system. Pirelli Cables and Systems
will develop and manufacture a high-performance cold dielectric
prototype cable, ENEL and Edison will contribute their systems
expertise, operational know-how, and facilities to evaluate the
advantages and applicability of HTS cable technology in transmission and
distribution networks. In addition, the new system will be subjected to
prolonged electrical and mechanical tests in the CISE Laboratories in
Milan. For information, contact Sergio Zannella, Edison SpA, Foro
Buonaparte 31, I-20121 Milano, Italy; telephone +39 02 62227295; telefax
+39 02 62223074; e-mail zannellas@edison.it.
Dramatic range extension and performance improvements were reported by
Illinois Superconductor Corporation recently, from the installation of
ISC's SpectrumMaster[R] Classic filter in a Code Division Multiple
Access (CDMA) commercial cell site in the United States. The operator
is conducting additional testing which may lead to the widespread
deployment of ISC's technology throughout its CDMA system. In the
evaluation, the SpectrumMaster[R] Classic filter was installed in a
rural site along a major interstate highway, and documented results show
expanded cell site coverage by more than 25%. Other documented benefits
of the test included decreased dropped and blocked calls and
significantly lower handset transmit power (3-5 dB), which can increase
cell capacity and extend cell phone talk time.
In other news, Illinois Superconductor Corporation announced the
introduction of its new GSM (Global System for Mobile Communications)
RangeMaster[R] filter system with ATP[TM], which will be field tested by
one of the world's largest cellular system equipment providers (OEMs).
The new product will be shipped within the next week for testing in a
"live" cellular system located in Europe. The new system, which is
expected to improve system sensitivity, combines high-performance
superconducting filters with cooled low-noise amplifiers, and typically
increases site coverage by as much as 70%, lowers dropped calls by up to
40%, and simplifies the location of new cell sites in comparison to
conventional filters. With All Temperature Performance (ATP[TM]), the
GSM RangeMaster[R] filter uniquely provides excellent performance,
whether the unit is in cold "superconducting" or warm
"nonsuperconducting" mode. First operational in 1992, GSM is an
international digital standard developed under the promotion of the
Conference des Administrations Europeenes des Postes et
Telecommunications (CEPT), the telecommunications industry
administration of 26 European countries. With more than 160 million
customers, GSM technology is deployed in approximately 160,000 cell
sites in 133 countries and areas around the world. Because of the wide
deployment of GSM technology, GSM customers can use their cellular
telephones domestically and when traveling internationally.
More information about Illinois Superconductor Corporation is available
on the Company's Web site at http://www.ilsc.com. Or contact Monique
Showalter, telephone (847) 391-9426, e-mail showalter@ilsc.com.
Contributed by Sreeparna Mitra
PREPRINTS
To obtain a particular preprint, contact the first author at the address
given at the end of the citation. Help us expand this list by sending
us your complete preprint. Please specify where and when your paper was
submitted. An * next to an entry indicates it is a correction or
revision of a previous entry. PACS codes and/or key words are given at
the end of the citation.
N. Adamopoulos and S. K. Patapis, "Effect of Interface Quality on
Magnetic Pinning Interaction." To be published in Physica C: Proc. of
the First Crete Euroconf. on Anomalous Complex Supercond. (ACS-1),
Heraklion, Greece, Sept. 25-Oct. 2, 1998. Section of Solid State
Physics, Department of Physics, University of Athens, Panepistimiopolis,
GR 15784 Athens, GREECE; telefax +30 1 725 7689. Key words: magnetic
pinning interaction, pinning force, high-Tc superconductor.
G. Aeppli, D. J. Bishop, C. Broholm, E. Bucher, S.-W. Cheong, P. Dai, Z.
Fisk, S. M. Hayden, R. Kleiman, T. E. Mason, H. A. Mook, T. G. Perring,
and A. Schroeder, "Neutron Scattering and the Search for Mechanisms of
Superconductivity." To be published in Physica C: Proc. of the First
Crete Euroconf. on Anomalous Complex Supercond. (ACS-1), Heraklion,
Greece, Sept. 25-Oct. 2, 1998. NEC Research Institute, Princeton, NJ
08540; telefax (609) 951-2481. Key words: neutron scattering,
superconductivity, exotic.
Ajay, "Role of Interlayer Coupling in the Superconducting State of
Layered Cuprate Superconductors." To be published in Physica C (in
press). #250 Condensed Matter Group, National Physical Laboratory, Dr.
K. S. Krishnan Road, New Delhi 110012, INDIA; telephone +91 11 574 3964;
telefax +91 11 575 2678; e-mail ajay@csnpl.ren.nic.in. Key words:
high-temperature layered superconductors, interlayer interactions,
charge carrier density, generalized energy-gap. 74.62.Bf; 74.80.Dm;
74.20.Fg.
J. F. Annett, "Unconventional Pairing in Anomalous Superconductors." To
be published in Physica C: Proc. of the First Crete Euroconf. on
Anomalous Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct.
2, 1998. H. H. Wills Physics Laboratory, University of Bristol, Royal
Fort, Tyndall Avenue, Bristol BS8 1TL, UNITED KINGDOM; telephone +44 117
9288752; telefax +44 117 9255624; e-mail james.annett@bristol.ac.uk.
Key words: superconductors, pairing, normal state.
Josef Ashkenazi, "Stripes, Carriers, and High-Tc in the Cuprates."
Department of Physics, University of Miami, P.O. Box 248046, Coral
Gables, FL 33124; e-mail ashkenazi@phyvax.ir.miami.edu; preprint also
available at http://xxx.lanl.gov/abs/cond-mat/9905172.
D. K. Aswal, M. Shinmura, Y. Hayakawa, and M. Kumagawa, "In-Situ High-
Temperature Optical Microscopic Observations of Nucleation, Growth and
Morphology of ReBa2Cu3Ox (Re=Nd,Y)." To be published in Studies of High
Temp. Supercond., Vol. 29, edited by A. Narlikar (Nova Science
Publishers, New York, 1999). Research Institute of Electronics,
Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8011, JAPAN; telephone
and telefax +81 53 478 1338; e-mail roaswal@eng.shizuoka.ac.jp
E. Balthes, M. Schiller, D. Schweitzer, I. Heinen, W. Strunz, E. Steep,
A.G.M. Jansen, and P. Wyder, "Correlation Between a New Frequency (F_0 =
13.2 T) and Anomalous Damping Effects of Magneto-Quantum Oscillations in
the 2D Organic Superconductor kappa-(BEDT-TTF)2I3." To be published in
Physica C: Proc. of the First Crete Euroconf. on Anomalous Complex
Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Grenoble
High Magnetic Field Laboratory, Centre National de la Recherche
Scientifique and Max Planck Institut fuer Festkoerperforschung, B.P.
166, F-38042 Grenoble Cedex 9, FRANCE; telefax +33 4 7685 5610; e-mail
balthes@labs.polycnrs-gre.fr. Key words: organic superconductors,
magneto-quantum oscillations, Fermi surface.
S. Beuven, M. Darula, O. Harnack, K. Karlovsky, and H. Kohlstedt, "On-
Chip Integration of HTS Josephson Oscillator and Mixer." To be
published in IEEE Trans. Appl. Supercond. Institut fuer Schicht- und
lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY.
M. Bick, G. Panaitov, N. Wolters, Y. Zhang, H. Bousack, A. I. Braginski,
U. Kalberkamp, H. Burkhardt, and U. Matzander, "A HTS rf SQUID Vector
Magnetometer for Geophysical Exploration." To be published in IEEE
Trans. Appl. Supercond. Institut fuer Schicht- und lonentechnik (ISI),
Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY.
James C. Booth, J. A. Beall, D. A. Rudman, L. R. Vale, and R. H. Ono,
"Geometry Dependence of Nonlinear Effects in High Temperature
Superconducting Transmission Lines at Microwave Frequencies." To be
published in J. Appl. Phys. National Institute of Standards and
Technology, Division 814.03, 325 Broadway, Boulder, CO 80303; telephone
(303) 497-7900; telefax (303) 497-3042; e-mail booth@boulder.nist.gov;
Web site
http://emtech.boulder.nist.gov/div814/pubs/downloads/hitcstuff.htm.
V. Bruyndoncx, J. G. Rodrigo, T. Puig, L. Van Look, V. V. Moshchalkov,
and R. Jonckheere, "Giant Vortex State in Perforated Aluminum
Microsquares." To be published in Phys. Rev. B. Laboratorium voor
Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven,
Celestijnenlaan 200 D, B-3001 Leuven, BELGIUM; telephone +32 16 32 7164;
telefax +32 16 32 7983; e-mail vital.bruyndoncx@fys.kuleuven.ac.be;
preprint also available at http://xxx.lanl.gov/abs/cond-mat/9905093.
74.60.Ec; 73.23.-b.
Shixun Cao, Takao Ookami, Katsuhiko Nishimura, and Katsunori Mori,
"Reentrant Behavior in Ho1-xNdxNi2B2C System." To be published in
Physica C (in press). Contact Katsunori Mori, Faculty of Engineering,
Toyama University, Gofuku 3190, Toyama 930-8555, JAPAN; telefax +81 764
45 6843; e-mail mori@eng.toyama-u.ac.jp. Key words: superconductivity,
magnetic order, Ho1-xNdxNi2B2C, borocarbide, electrical resistivity,
magnetization. 74.25.-q; 74.25.Ha; 74.70.Dd.
Manuel Cardona, "Raman Scattering in High-Tc Superconductors: Phonons,
Electrons, and Electron-Phonon Interaction." To be published in Physica
C: Proc. of the First Crete Euroconf. on Anomalous Complex Supercond.
(ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Max-Planck-Institut
fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart,
GERMANY; telephone +49 711 689 1710; telefax +49 711 689 1712; e-mail
cardona@cardix.mpi-stuttgart.mpg.de. Key words: Raman spectroscopy, IR
spectroscopy, superconductors, electron-phonon interaction.
Selahattin Celebi, "Comparative ac Susceptibility Analysis on Bi-(Pb)-
Sr-Ca-Cu-O High-Tc Superconductors." To be published in Physica C (in
press). Department of Physics, Faculty of Science and Arts, Karadeniz
Technical University, 61080 Trabzon, TURKEY; telephone +90 462 325 8244;
telefax +90 462 325 3195; e-mail celebi@risc01.ktu.edu.tr. Key words:
Bi-(Pb)-Sr-Ca-Cu-O high-Tc superconductors, ac susceptibility, critical
current density. 74.60.Ge; 74.72.Fq.
J. H. Cho, "Critical State Generated by Isotropic Columnar Defects in a
Bi2Sr2CaCu2O8 Single Crystal." To be published in Physica C (in press).
RCDAMP, Department of Physics, Pusan National University, Jangjun-Dong
30, Kumjeong-Ku, Pusan 609-735, SOUTH KOREA; telephone +82 51 510 2968;
telefax +82 51 515 2390; e-mail jinhcho@hyowon.pusan.ac.kr. Key words:
critical states, isotropic columnar defects, Bi2Sr2CaCu2O8, single
crystal. 74.60.Ge; 74.72.Hs; 74.60.Jg; 74.25.Ha.
J. H. Claassen, James C. Booth, J. A. Beall, D. A. Rudman, L. R. Vale,
and R. H. Ono, "Nonlinear Inductive Response of High Temperature
Superconducting Films Measured by the Mutual Inductance Technique." To
be published in Appl. Phys. Lett. Naval Research Laboratory,
Washington, DC 20375-5343; James C. Booth's telephone at NIST (303) 497-
7900; telefax (303) 497-3042; e-mail booth@boulder.nist.gov; Web site
http://emtech.boulder.nist.gov/div814/pubs/downloads/hitcstuff.htm.
X. Cui, F. A. List, D. M. Kroeger, A. Goyal, D. F. Lee, J. E. Mathis, E.
D. Specht, P. M. Martin, R. Feenstra, D. T. Verebelyi, D. K. Christen,
and M. Paranthaman, "Continuous Growth of Epitaxial CeO2 Buffer Layers
on Rolled Ni Tapes Electron Beam Evaporation." To be published in
Physica C (in press). Metals and Ceramics Division, Oak Ridge National
Laboratory, Bldg. 4500S, M/S 6116, P.O. Box 2008, Oak Ridge, TN 37831-
6116; telephone (423) 574-3719; telefax (423) 574-7659; e-mail
cuix@ornl.gov. Key words: applications of high-Tc superconductors,
continuous deposition, biaxial texture, rolled Ni substrates, E-beam
evaporation.
Marc Currie, Chia-Chi Wang, Roman Sobolewski, and Thomas Y. Hsiang,
"Picosecond Nodal Testing of Centimeter-Size Superconducting Nb
Microstrip Interconnects." To be published in Appl. Supercond. (in
press). Contact Roman Sobolewski, Department of Electrical Engineering
and Laboratory for Laser Energetics, University of Rochester, P.O. Box
270231, Rochester, NY 14627; telephone (716) 275-1551; telefax (716)
275-2073; e-mail sobolewski@ece.rochester.edu.
Marian Darula, "High-Tc Josephson Junction Arrays and Their
Applications." To be published in Superconductivity in Networks and
Mesoscopic Systems, edited by Giovannella/Lambert. Institut fuer
Schicht- und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425
Juelich, GERMANY.
Z. John Deng, Nobuyuki Yoshikawa, Stephen R. Whiteley, and Theodore Van
Duzer, "Design and Testing of Data-Driven Self-Timed RSFQ Shift
Register." To be published in Appl. Supercond. (in press). Contact
Theodore Van Duzer, Department of Electrical Engineering and Computer
Sciences, University of California at Berkeley, Berkeley, CA 94706;
telephone (510) 642-3306; telefax (510) 642-5854; e-mail
vanduzer@eecs.berkeley.edu.
R. Dittmann, J.-K. Heinsohn, A. I. Braginski, and C. L. Jia,
"Fabrication of YBa2Cu3O7 Ramp-Type Junctions by Interface Treatments."
To be published in IEEE Trans. Appl. Supercond. Institut fuer Schicht-
und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY.
S.-L. Drechsler, S. V. Shulga, K.-H. Mueller, G. Fuchs, J.
Freudenberger, H. Eschrig, L. Schultz, M. S. Golden, H. von Lips, J.
Fink, V. N. Narozhnyi, H. Rosner, P. Zahn, A. Gladun, D. Lipp, A.
Kreyssig, M. Loewenhaupt, K. Koepernik, K. Winzer, and K. Krug,
"Superconducting Rare Earth Transition Metal Borocarbides." To be
published in Physica C: Proc. of the First Crete Euroconf. on Anomalous
Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
Institut fuer Festkoerper- und Werkstofforschung Dresden, Postfach
270016, D-01171 Dresden, GERMANY; telefax +49 351 4659 537; e-mail
drechsler@ifw-dresden.de. Key words: metal borocarbides, local density
approximation (LDA), superconductivity.
M. Dressel, "On the Order Parameter of Bechgaard Salts." To be
published in Physica C: Proc. of the First Crete Euroconf. on Anomalous
Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
I. Physikalisches Institut, Universitaet Stuttgart, Pfaffenwaldring 57,
D-70550 Stuttgart, GERMANY; telephone +49 711 685 4947; telefax +49 711
685 4886; e-mail dressel@pi1.physik.uni-stuttgart.de. Key words: spin
density wave, superconductivity, Bechgaard salts, optical properties,
acoustic properties.
P. Esquinazi, A. Setzer, D. Fuchs, Y. Kopelevich, E. Zeldov, and C.
Assmann, "Vortex Avalanches in Nb Thin Films: Global and Local
Magnetization Measurements." Submitted to Phys. Rev. B. Department of
Superconductivity and Magnetism, Universitaet Leipzig, Linnestrasse 5,
D-04103 Leipzig, GERMANY. 74.76.Db; 74.40.+k; 74.60.Ge.
Nicholas J. Exon, Mark N. Keene, Julian S. Satchell, Nigel G. Chew,
Matthew J. Wooliscroft, Karan Lander, and Richard G. Humphreys, "A Low
Noise HTS SQUID Magnetometer with an On-Chip Pickup Loop Coupled via an
Intermediate Flux Transformer." To be published in Appl. Supercond. (in
press). Defense Research Agency, Malvern, Worcestershire WR14 3PS,
UNITED KINGDOM.
I. M. Fita, V. P. Dyakonov, V. I. Kamenev, R. Puzniak, and H. Szymczak,
"Pressure-Controlled Oxygen Order and Superconductivity in REBaCuO
(RE=Y,Nd) Near the Metal-Insulator Transition." To be published in
Physica C: Proc. of the First Crete Euroconf. on Anomalous Complex
Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Donetsk
Physical and Technical Institute, National Academy of Sciences, R.
Luxemburgstr. 72, 340114 Donetsk, UKRAINE; e-mail
fita@host.dipt.donetsk.ua. Key words: REBaCuO compounds, pressure
effect, oxygen ordering, charge transfer, superconductivity appearance.
Giorgio Flor, Gaetano Chiodelli, Giorgio Spinolo, and Paolo Ghigna,
"NdBa2Cu3O6+d (Nd-123): Low- and High-Temperature Conductivity." To be
published in Physica C (in press). Contact Paolo Ghigna, INCM, CSTE-CNR
and Dipartimento di Chimica Fisica, Universita di Pavia, Viale Taramelli
16, I-27100 Pavia, ITALY; telephone +39 0382 507 574; e-mail
paolo@chifis.unipv.it. Key words: hole-injection sequence, Nd-123.
74.20.Mn; 71.38.+i.
A. Gilabert, A. Hoffmann, M. G. Medici, and Ivan K. Schuller,
"Photodoping Effects in High Critical Temperature Superconducting Films
and Josephson Junctions." Submitted to J. Supercond. Contact A.
Hoffmann, Department of Physics 0350, University of California at San
Diego, 9500 Gilman Drive, La Jolla, CA 92093-0350; telephone (619) 534-
7161; telefax (619) 534-0173; e-mail hoffmann@ucsd.edu. Key words:
doping, Josephson junctions, photoconductivity, superconductivity, thin
films.
L. Glemot, J. P. Brison, J. Flouquet, A. I. Buzdin, and D. Jaccard,
"Strong Coupling Superconductivity in Heavy Fermion Systems." To be
published in Physica C: Proc. of the First Crete Euroconf. on Anomalous
Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
Contact J. P. Brison, Centre de Recherches sur les Tres Basses
Temperatures, CNRS, BP 166, F-38042 Grenoble Cedex 9, FRANCE; telephone
+33 4 7688 9759; telefax +33 4 7688 5096; e-mail brison@labs.polycnrs-
gre.fr. Key words: heavy fermion systems, UBe13, strong coupling.
74.20.Mn; 74.60.Ec; 74.62.Fj; 74.70.Tx.
S. Glenis, T. Yuen, C. L. Lin, J. A. Zan, and T. Mihalisin, "Comparing
the Effects of Oxygen Content on the Superconducting Properties of
YBa2Cu3Ox and RBa2Cu3Ox with R=Nd,Eu and Gd." To be published in
Physica C: Proc. of the First Crete Euroconf. on Anomalous Complex
Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Section
of Solid State Physics, Department of Physics, University of Athens, GR
15784 Zografos, Athens, GREECE; telefax +30 1 725 7689; e-mail
sglenis@atlas.uoa.gr. Key words: oxygen content, superconductivity,
YBa2Cu3Ox, RBa2Cu3Ox.
Wolfgang Goeb, Wolfgang Lang, Johannes Pedarnig, Roman Roessler, and
Dieter Baeuerle, "Magnetic Field and Current Density Dependence of the
Mixed-State Hall Effect in Bi2Sr2CaCu2Ox." To be published in Physica
C: Proc. of the First Crete Euroconf. on Anomalous Complex Supercond.
(ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Institut fuer
Materialphysik der Universitaet Wien and Ludwig Boltzmann Institut fuer
Festkoerperphysik, Kopernikusgasse 15, A-1060 Wien, AUSTRIA; e-mail
goeb@merlin.pap.univie.ac.at. Key words: magnetic field, current
density dependence, Bi2Sr2CaCu2Ox.
G. Goll and H. V. Loehneysen, "Point-Contact Spectroscopy on the Heavy-
Fermion Superconductor UPt3 in the Normal and Superconducting States."
To be published in Physica C: Proc. of the First Crete Euroconf. on
Anomalous Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct.
2, 1998. Physikalisches Institut, Universitaet Karlsruhe,
Engesserstrasse 7, D-76128 Karlsruhe, GERMANY; telephone +49 721 608
3540; telefax +49 721 608 6103; e-mail gernot.goll@phys.uni-
karlsruhe.de. Key words: point-contact spectroscopy, heavy-fermion
superconductor, UPt3. 74.70.Tx; 73.40.Jn; 74.80.Fp.
A. I. Golovashkin, N. V. Anshukova, L. I. Ivanova, and A. P. Rusakov,
"Superstructural Ordering and Phase Transitions in Oxide HTSC." To be
published in Physica C: Proc. of the First Crete Euroconf. on Anomalous
Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow,
RUSSIA; e-mail golov@sci.lebedev.ru.
R. S. Gonnelli, G. A. Ummarino, and V. A. Stepanov, "Eliashberg
Equations, Pair Symmetry and Tunnel Density of States in the Optimally
Doped High-Tc Superconductor Bi2Sr2CaCu2O8+x." To be published in
Physica C: Proc. of the First Crete Euroconf. on Anomalous Complex
Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. INFM-
Dipartimento di Fisica, Politecnico di Torino, I-10129 Torino, ITALY;
telefax +39 011 564 7399; e-mail gonelli@polito.it. Key words:
Eliashberg equations, pair symmetry, tunnel density of states.
74.50.+r; 74.20.-z; 74.72.Hs.
S. N. Gordeev, A. P. Rassau, R. M. Langan, P.A.J. de Groot, V. B.
Geshkenbein, R. Gagnon, and L. Taillefer, "Resistivity of Clean
YBa2Cu3O7-d in the Pinned-Liquid State." Submitted to Phys. Rev. B.
Department of Physics, University of Southampton, Southampton SO17 1BJ,
UNITED KINGDOM; telephone +44 1703 592077; telefax +44 1703 593910; e-
mail sg@phys.soton.ac.uk. 74.25.Fy; 74.60.Ge; 74.72.Bk.
G. C. Han and C. K. Ong, "Field Dependence of ac Susceptibility and Its
Anistropy in a Textured (BiPb)2Sr2Ca2Cu3Oy/Ag Tape." To be published in
Physica C (in press). Department of Physics, National University of
Singapore, 10 Kent Ridge Crescent, 119260, SINGAPORE; telephone +65 874
7970; telefax +65 778 2968; e-mail hangc@dsi.nus.edu.sg. Key words: ac
susceptibility, (BiPb)2Sr2Ca2Cu3Oy/Ag tape, dc magnetic field, tape
plane, 3D anisotropic scaling. 74.60.Ge; 74.60.Jg; 74.60.Ec.
Shingo Hanazato, Takehiko Mori, Hatsumi Mori, and Shoji Tanaka,
"Transport Properties of alpha"-Phase Organic Conductors, (BEDT-
TTF)2CsHg(SCN)4 and (BEDT-TTF)2K1.4Co(SCN)4." To be published in
Physica C (in press). Contact Takehiko Mori, Department of Organic and
Polymeric Materials, Tokyo Institute of Technology, Okayama, Tokyo 152-
8552, JAPAN; telephone +81 3 5734 2427; telefax +81 3 5734 2876; e-mail
takehiko@o.cc.titech.ac.jp. Key words: organic conductor, electronic
structure, metal-insulator transition.
Oliver Harnack, Stephan Beuven, Marian Darula, Hermann Kohlstedt,
Michael Tarasov, Evgueni Stephantsov, and Zdravko Ivanov,
"Characterization of Millimeter and Submillimeter Wave Mixers Based on
High-Tc Superconductor Structures." Submitted to the 6th IEEE Int.
Conf. on THz Electronics, Sept. 1998. Institut fuer Schicht- und
lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY. Key words: high-Tc superconductor, Josephson mixer, hot-
electron bolometer mixer.
D. F. He, H.-J. Krause, Y. Zhang, M. Bick, H. Soltner, N. Wolters, W.
Wolf, and H. Bousack, "HTS SQUID Magnetometer with SQUID Vector
Reference for Operation in Unshielded Environment." To be published in
IEEE Trans. Appl. Supercond.: Proc. of the 1998 Appl. Supercond. Conf.
(ASC), Palm Desert, Calif., Sept. 13-18, 1998. Institut fuer Schicht-
und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY.
R. Hohmann, C. Lienerth, Y. Zhang, H. Bousack, G. Thummes, and C.
Heiden, "Comparison of Low Noise Cooling Performance of a Joule-Thomson
Cooler Using a HT SQUID." To be published in IEEE Trans. Appl.
Supercond.: Proc. of the 1998 Appl. Supercond. Conf. (ASC), Palm
Desert, Calif., Sept. 13-18, 1998. Institut fuer Schicht- und
lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY.
R. Hohmann, M. Maus, D. Lomparski, M. Grueneklee, Y. Zhang, H.-J.
Krause, H. Bousack, and A. I. Braginski, "Aircraft Wheel Testing with
Machine-Cooled HTS SQUID Gradiometer System." To be published in IEEE
Trans. Appl. Supercond.: Proc. of the 1998 Appl. Supercond. Conf.
(ASC), Palm Desert, Calif., Sept. 13-18, 1998. Institut fuer Schicht-
und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY.
John R. Hull, "Levitation Applications Using High-Temperature
Superconductors." To be published in JOM. Energy Technology Division,
Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439.
Alexander Ignatov, "Relationship Between the Electronic and Local
Structure in BaBi1-xPbxO3 and Ba1-xKxBiO3 Perovskites." To be published
in J. Synchrotron Radiation. Department of Physics, Southern Illinois
University, Carbondale, IL 62901-4401; telephone (618) 453-7126; telefax
(618) 453-1056; e-mail ignatov@physics.siu.edu. Key words: charge
disproportionation, electronic structure, local structure, XAFS,
perovskites.
Alexander Ignatov, Josef Feldhaus, Vladimir Chernov, and Andrey Ivanov,
"The Local Structure of the CuO2 Plane in Nd2-xCexCuO4-d: An X-ray
Absorption Study." To be published in J. Synchrotron Radiation.
Department of Physics, Southern Illinois University, Carbondale, IL
62901-4401; telephone (618) 453-7126; telefax (618) 453-1056; e-mail
ignatov@physics.siu.edu. Key words: local structure, XAFS, domains,
superconductors.
M. Ikebe, H. Fujishiro, Y. Obi, H. Fujimori, and S. Morohashi, "On
Anomalous Temperature Dependence of H_{c2[perp.]} in Natural and
Artificial Layer Superconductors." To be published in Physica C (in
press). Faculty of Engineering, Department of Materials Science, Iwate
University, 4-3-5 Ueda, Morioka 020-8551, JAPAN; e-mail ikebe@iwate-
u.ac.jp. Key words: H_{c2[perp.]}, artificial-layer superconductor,
natural-layer superconductor.
A. Jukna, S. H. Yun, S. Balevicius, and U. O. Karlsson, "Electric
Properties of Planar Ag/HgBa2CaCu2O6+d Interface." To be published in
Physica C (in press). High Power Pulse Laboratory, Semiconductor
Physics Institute, A. Gostauto 11, 2600 Vilnius, LITHUANIA; telephone
+370 261 8547; telefax +370 262 7123; e-mail arjuk@uj.pfi.lt. Key
words: high-Tc superconductors, Ag/HgBa2CaCu2O6+d interface, contact
resistance. 74.50.+r.
W. N. Kang, Wan-Seon Kim, S. J. Oh, Sung-Ik Lee, D. H. Kim, C. H. Choi,
H.-C. Ri, and C. W. Chu, "Universal Scaling of Hall Resistivity in Clean
and Moderately Clean Limits for Hg- and Tl-Based Superconductors."
Submitted to Phys. Rev. Lett. National Creative Research Initiative
Center for Superconductivity, Department of Physics, Pohang University
of Science and Technology, Pohang 790-784, SOUTH KOREA; e-mail
wnkang@postech.ac.kr; preprint also available at
http://xxx.lanl.gov/abs/cond-mat/9905201. 74.60.Ge; 74.25.Fy; 74.72.Gr;
74.76.-w.
A. S. Katz, S. I. Woods, E. J. Singley, T. W. Li, M. Xu, D. G. Hinks, R.
C. Dynes, and D. N. Basov, "Interlayer Conductivity in the
Superconductor Tl2Ba2CuO6+d: Energetics and Energy Scales." Submitted
to Phys. Rev. Lett. Department of Physics, University of California at
San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0319; e-mail
akatz@ucsd.edu; preprint also available at http://xxx.lanl.gov/abs/cond-
mat/9905170. 78.30.-j; 74.72.Fq; 74.62.Dh; 74.25.Gz.
M. Knoll and F. H. Uhlman, "Design Analysis of Metallic Single Electron
Tunneling Circuits." To be published in Appl. Supercond. (in press).
Department of Fundamentals and Theory of Electrical Engineering,
Technical University of Ilmenau, D-98684 Ilmenau, GERMANY.
S. Kokkaliaris, P.A.J. de Groot, S. N. Gordeev, A. A. Zhukov, R. Gagnon,
and L. Taillefer, "Onset of Plasticity and Hardening of the Hysteretic
Response in the Vortex System of YBa2Cu3O7-d." To be published in Phys.
Rev. Lett. Department of Physics and Astronomy, University of
Southampton, Highfield, Southampton SO17 1BJ, UNITED KINGDOM; telephone
+44 1703 592058; telefax +44 1703 593910; e-mail sk@phys.soton.ac.uk.
74.60.Ge; 74.60.Jg; 74.72.Bk.
A. A. Kordyuk, V. V. Nemoshkalenko, R. V. Viznichenko, T. Habisreuther,
and W. Gawalek, "Determination of Critical Current Density in Melt-
Processed HTS Bulks from Levitation Force Measurements." Submitted to
Appl. Phys. Lett. Institute of Metal Physics, National Academy of
Sciences of Ukraine, 36 Vernadsky str., Kyiv 252680, UKRAINE; telephone
+380 44 444 1005; telefax +380 44 444 2561; e-mail kord@imp.kiev.ua;
preprint also available at http://xxx.lanl.gov/abs/cond-mat/9905032.
Miodrag L. Kulic and Oleg V. Dolgov, "Anisotropic Impurities in
Anisotropic Superconductors." Physikalisches Institut, Universitaet
Bayreuth, D-95440 Bayreuth, GERMANY; Oleg V. Dolgov's e-mail at
Universitaet Tuebingen oleg.dolgov@uni-tuebingen.de; preprint also
available at http://xxx.lanl.gov/abs/cond-mat/9904407. 74.20.-z;
74.20.Fg.
S. G. Lachenmann, A. Foerster, I. Friedrich, D. Uhlisch, Th. Schaepers,
A. Kastalsky, and A. A. Golubov, "Superconductor/Semiconductor Step
Junctions: The Basic Element for Hybrid Three Terminal Devices." To be
published in Appl. Supercond. (in press). Institut fuer Schicht- und
lonentechnik, Forschungszentrum Juelich, D-52425 Juelich, GERMANY.
S. L. Li, H. H. Wen, and Z. X. Zhao, "Modeling and Simulation on the
Magnetization in Field-Cooling and Zero-Field-Cooling Processes." To be
published in Physica C (in press). Contact H. H. Wen, National
Laboratory for Superconductivity, Institute of Physics and Center for
Condensed Matter Physics, Chinese Academy of Sciences, P.O. Box 603,
Beijing 100080, PEOPLE'S REPUBLIC OF CHINA; telephone +86 10 6258 2179;
telefax +86 10 6256 2605; e-mail hhwen@aphy.iphy.ac.cn. Key words:
magnetization, flux pinning, Monte Carlo simulation.
A. P. Litvinchuk, L. Boerjesson, C. Thomsen, and C. W. Chu, "Magnetic
Excitations in PrBa2Cu4O8 Explored by Raman Scattering." Preprint
#99:040; submitted to the Proc. of the Int. Conf. on Solid State
Spectroscopy (ICSSS), Schwaebisch Gmuend, Germany, Sept. 5-7, 1999; to
be published in Phys. Status Solidi (b). Department of Physics and
Texas Center for Superconductivity, University of Houston, Houston, TX
77204-5932; telephone (713) 743-8309; telefax (713) 743-8201; e-mail
litvin@bayou.uh.edu. 74.25.Gz; 75.30.Et; 78.30.Er.
H. B. Liu, Paulo J. Ferreira, and J. B. Vander Sande, "Jc Enhancement of
Bi2Sr2CaCu2O8/Ag Thick Films Melt-Grown Under an Elevated Magnetic Field
(0-10 T)." To be published in Physica C (in press). Contact Paulo J.
Ferreira, Department of Materials Science and Engineering, Massachusetts
Institute of Technology, Cambridge, MA 02139; telephone (617) 253-0222;
telefax (617) 258-7874; e-mail ferreira@mit.edu. Key words: elevated
magnetic field, Jc enhancement, Bi2Sr2CaCu2O8/Ag thick films.
H. B. Liu, P. J. Ferreira, J. B. Vander Sande, and A. Otto, "Bi-2212/Ag
Tapes Melt-Grown Under an Elevated Magnetic Field (0-10 T)." To be
published in Physica C (in press). Contact P. J. Ferreira, Department
of Materials Science and Engineering, Massachusetts Institute of
Technology, Cambridge, MA 02139; telephone (617) 253-0222; telefax (617)
258-7874; e-mail ferreira@mit.edu. Key words: Bi-2212 tapes, magnetic
field, texture.
F. Mrowka, M. Wurlitzer, P. Esquinazi, E. Zeldov, T. Tamegai, S. Ooi, K.
Rogacki, and B. Dabrowski, "On the Temperature Dependence of the Lower
Critical Field of High-Tc Superconducting Crystals Near Tc." To be
published in Phys. Rev. B (in press). Department of Superconductivity
and Magnetism, Universitaet Leipzig, Linnestrasse 5, D-04103 Leipzig,
GERMANY.
A. K. Nguyen and A. Sudbo, "Topological Phase-Fluctuations, Amplitude
Fluctuations, and Criticality in Extreme Type-II Superconductors."
Norwegian University of Science and Technology, N-7034 Trondheim,
NORWAY. 74.20.De; 74.25.Dw; 74.25.Ha; 74.60.Ec.
Terukazu Nishizaki, Tomoyuki Naito, and Norio Kobayashi, "Effects of the
Weak Disorder on the Vortex Phase Diagram and the Second Peak in
Untwinned YBa2Cu3Oy Single Crystals." To be published in Physica C:
Proc. of the First Crete Euroconf. on Anomalous Complex Supercond. (ACS-
1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Institute for Materials
Research, Tohoku University, Sendai 980-8577, JAPAN; telefax +81 22 215
2026; e-mail terukazu@imr.tohoku.ac.jp. Key words: magnetization,
untwinned YBa2Cu3Oy, vortex phase diagram.
B. Normand, D. F. Agterberg, and T. M. Rice, "Two-Band Superconductivity
in the Doped Spin Ladder La1-xSrxCu2.5." To be published in Physica C:
Proc. of the First Crete Euroconf. on Anomalous Complex Supercond. (ACS-
1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Instituet fuer Physik,
Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel, SWITZERLAND;
telefax +41 61 267 3784; e-mail normand@ubaclu.unibas.ch. Key words:
superconductivity, LaCuO2.5, spin ladder.
Y. Obi, M. Ikebe, T. Kubo, and H. Fujimori, "Oscillation Phenomenon of
Transition Temperatures in Nb/Co and V/Co Superconductor/Ferromagnet
Multilayers." To be published in Physica C (in press). Institute for
Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai
980-8577, JAPAN; telephone +81 22 215 2097; telefax +81 22 215 2096; e-
mail obi@imr.tohoku.ac.jp. Key words: oscillation, Nb/Co, V/Co.
Satoru Okayasu and Hidehito Asaoka, "The Order of Phase Transition of
Reentrant Line in Detwinned YBCO Single Crystal." To be published in
Physica C: Proc. of the First Crete Euroconf. on Anomalous Complex
Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Japan
Atomic Energy Research Institute Tokai, Ibaraki 319-1195, JAPAN; e-mail
okayasu@popsvr.tokai.jaeri.go.jp. Key words: detwinned YBCO single
crystal, peak effect, reentrant properties.
Andrzej M. Oles, Louis Felix Feiner, and Jan Zaanen, "Quantum Melting of
Magnetic Long-Range Order Near Orbital Degeneracy: Classical Phases and
Gaussian Fluctuations." Max-Planck-Institut fuer Festkoerperforschung,
Heisenbergstrasse 1, D-70569 Stuttgart, GERMANY; e-mail
amoles@audrey.mpi-stuttgart.mpg.de; preprint also available at
http://xxx.lanl.gov/abs/cond-mat/9904355. 71.27.+a; 75.10.-b; 75.30.Kz;
75.30.Ds.
A. V. Pan, F. Ciovacco, P. Esquinazi, and M. Lorenz, "The Depinning of a
Driven Vortex Lattice in High-Tc Films." To be published in Phys. Rev.
B (in press). Department of Superconductivity and Magnetism, Institut
fuer Experimentelle Physik II, Universitaet Leipzig, Linnestrasse 5, D-
04103 Leipzig, GERMANY; e-mail pan@physik.uni-leipzig.de.
E. Papadopoulou, P. Nordblad, P. Svedlindh, R. Schoeneberger, and R.
Gross, "The Ageing Effect in a Superconducting Sample Displaying the
Paramagnetic Meissner Effect." To be published in Physica C: Proc. of
the First Crete Euroconf. on Anomalous Complex Supercond. (ACS-1),
Heraklion, Greece, Sept. 25-Oct. 2, 1998. Department of Materials
Science, Uppsala University, Box 534, S-751 21 Uppsala, SWEDEN; telefax
+46 1847 135 72; e-mail evie.papadopoulou@angstrom.uu.se. Key words:
ageing effect, superconducting sample, paramagnetic Meissner effect.
S. Pavard, D. Bourgault, C. Villard, and R. Tournier, "Critical Current
Density of 165 kA/cm^2 at 4 K in Bulk Bi2212/MgO Textured by
Solidification in a High Magnetic Field and Hot Forging." To be
published in Physica C (in press). MATFORMAG, Laboratoire de
Cristallographie, CRETA, Centre National de la Recherche Scientifique
(CNRS), 25 Avenue des Martyrs, BP 166, F-38042 Grenoble Cedex 9, FRANCE;
telephone +33 4 7688 9035; telefax +33 4 7688 1280; e-mail
sybille.pavard@labs.polycnrs-gre.fr. Key words: critical current
density, texturing, Bi2212/MgO. 74.72.Hs; 74.60.Jg.
A. K. Pradhan, M. Muralidhar, M. R. Koblischka, M. Murakami, K. Nakao,
and N. Koshizuka, "Evidence of Strong Flux Pinning in Melt-Processed
Ternary (Nd-Eu-Gd)Ba2Cu3Oy Superconductors." To be published in Appl.
Phys. Lett. (in press). Superconductivity Research Laboratory,
International Superconductivity Technology Center (ISTEC), 10-13
Shinonome 1-chome, Koto-ku, Tokyo 135-0062, JAPAN; telefax +81 3 3536-
5714 or -5717; e-mail pradhan@istec.or.jp. 74.60.Ge; 74.60.Jg.
Mladen Prester, "Experimental Evidence of a Fractal Dissipative Regime
in High-Tc Superconductors." To be published in Phys. Rev. B.
Institute of Physics, University of Zagreb, P.O.B. 304, HR-10 000
Zagreb, CROATIA; telephone +385 1 46 80-211 or -397; telefax +385 1 46
80-399; e-mail prester@ifs.hr; preprint also available at
http://xxx.lanl.gov/abs/cond-mat/9905095. 64.60.Ak; 74.50.+r.
Leonid P. Pryadko, Steven A. Kivelson, V. J. Emery, Yaroslaw B. Bazaliy,
and Eugene A. Demler, "Topological Doping and the Stability of Stripe
Phases." Report #IASSNS-HEP-99/46. School of Natural Sciences,
Institute for Advanced Study, Princeton, NJ 08540; telephone (609) 734-
8069; telefax (609) 951-4489; e-mail leonid@sns.ias.edu; preprint also
available at http://xxx.lanl.gov/abs/cond-mat/9905146.
E. Sudhakar Reddy and T. Rajasekharan, "Microstructural and Magnetic
Properties of Textured GdBa2Cu3Oy/Gd2BaCuO5 Composites Fabricated from
Gd2BaCuO5 Preforms." To be published in Physica C (in press).
Department of Superconductivity, University of Tokyo, Hongo 7-3-1,
Bunkyo-ku, Tokyo 113-8656, JAPAN; telephone +81 3 3812 211, ext. 7711;
telefax +81 3 5689 0574; e-mail treddy@hongo.ecc.u-tokyo.ac.jp. Key
words: GdBa2Cu3Oy superconductor, transition temperature, infiltration
and growth process.
Aldo H. Romero, David W. Brown, and Katja Lindenberg, "Effects of
Dimensionality and Anisotropy on the Holstein Polaron." Max-Planck-
Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569
Stuttgart, GERMANY; Katja Lindenberg's e-mail at University of
California, San Diego kl@hypatia.ucsd.edu; preprint also available at
http://xxx.lanl.gov/abs/cond-mat/9905148. 71.38.+i; 71.15.-m; 71.35.Aa;
72.90.+y.
B. Ruck, R. Schmitz, N. Thyssen, B. Hermanns, H. Kohlstedt, and Susanne
Lomatch, "Experimental Realization of a 3D Integrated RSFQ T-Flip-Flop
Using Stacktrons." Institut fuer Schicht- und lonentechnik (ISI),
Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY.
Shoichi Sakamoto, Hideki Matsumoto, Tomio Koyama, and Masahiko Machida,
"Voltage-Biased I-V Characteristics in the Multi-Josephson Junction
Model of High Tc Superconductors." Department of Applied Physics,
Seikei University, Kichijoji Kitamachi 3-3-1, Musashino-Shi, Tokyo 180-
8633, JAPAN; e-mail matumoto@apm.seikei.ac.jp.
M. M. Sanchez, A. Avella, and F. Mancini, "The Van Hove Scenario in the
Hubbard Model with Correlated Hopping." To be published in Physica C:
Proc. of the First Crete Euroconf. on Anomalous Complex Supercond. (ACS-
1), Heraklion, Greece, Sept. 25-Oct. 2, 1998. Dipartimento di Scienze
Fisiche 'E.R. Caianiello,' UnitaINFM di Salerno, Universita degli Studi
di Salerno, Via S. Allende, I-84081 Baronissi (SA), ITALY; telefax +39
089 96 5275; e-mail mancini@vaxsa.csied.unisa.it. Key words: Hubbard
model, composite operator method, Van Hove singularity.
Edson Sardella, M. M. Doria, and P.R.S. Netto, "Matching Fields of a
Long Superconducting Film." Departamento de Fisica, Universidade
Estadual Paulista, Caixa Postal 473, 17033-360 Bauru-SP, BRAZIL; e-mail
sardella@bauru.unesp.br; preprint also available at
http://xxx.lanl.gov/abs/cond-mat/9905162. 74.60.Ec; 74.60.Ge.
N. V. Sarlis and S. K. Patapis, "A Percolation Model for the Explanation
of Fractal Paraconductivity Behavior in a YBaCuO Sample." To be
published in Physica C: Proc. of the First Crete Euroconf. on Anomalous
Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
Contact S. K. Patapis, Solid State Section, Department of Physics,
University of Athens, Panepistimiopolis, GR-15784 Athens, GREECE;
telefax +30 1 725 7689. Key words: superconductivity, fluctuation
effects, percolation, fractal. 74.72.Bk; 74.76.-w; 74.40.+k.
Peter Selders, Ana M. Castellanos, Mathias Vaupel, and Roger
Woerdenweber, "Reduction of 1/f Noise in HTS-SQUIDS by Artificial
Defects." To be published in IEEE Trans. Appl. Supercond. Institut
fuer Schicht- und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-
52425 Juelich, GERMANY.
Yorozu Shinichi, Hashimoto Yoshihito, Numata Hideaki, Koike Masashi, and
Tahara Shuichi, "Full Operation of a Switching Node Circuit for
Superconducting Ring Network." To be published in Appl. Supercond. (in
press). Fundamental Research Laboratories, NEC Corporation, 34
Miyukigaoka, Tsukuba, Ibaraki, JAPAN; telephone +81 298 50 2634; telefax
+81 298 56 6139; e-mail yorozu@frl.cl.nec.co.jp. Key words:
superconducting device, superconducting circuits, superconducting
system, processor interconnection, pipelined ring interconnection.
B. Starmark, P. Delsing, D. B. Haviland, and T. Claeson, "Noise
Measurements of Single Electron Transistors Using a Transimpedance
Amplifier." To be published in Appl. Supercond. (in press). Department
of Microelectronics and Nanoscience, Goeteborg University and Chalmers
University of Technology, S-41296 Goeteborg, SWEDEN.
Masanori Sugahara and Syuhei Mitani, "Experimental Evidence of Pairing
Fractional Quantum Hall Effect State in High Temperature Oxide
Superconductors Caused by ||c Zero-Point Oscillation in CuO2 Layer." To
be published in Physica C: Proc. of the First Crete Euroconf. on
Anomalous Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct.
2, 1998. Faculty of Engineering, Yokohama National University,
Tokiwadai, Hodogaya, Yokohama 240-8501, JAPAN; telephone +81 45 335
1451; telefax +81 45 338 1157; e-mail sugahara@dnj.ynu.ac.jp. Key
words: high-temperature oxide superconductors, fractional quantum Hall
effect, CuO2 layer.
M. D. Sumption and S. Takacs, "Flux Pinning in the Weak Layers of
Superconducting Heterogeneous Structures." To be published in Physica C
(in press). Department of Materials Science and Engineering, 477 Watts
Hall, Ohio State University, 2041 College Avenue, Columbus, OH 43210-
1179; telephone (614) 688-3684; telefax (614) 292-1537; e-mail
mdsumption+@osu.edu. Key words: pinning, anisotropy, proximity
effects, boundary conditions.
Y. Tanuma, Y. Tanaka, M. Ogata, and S. Kashiwaya, "Local Density of
States of Quasiparticles Near the Surface of t-t'-t"-J Model." To be
published in Physica C: Proc. of the First Crete Euroconf. on Anomalous
Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
Contact Y. Tanaka, CREST, Department of Applied Physics, Nagoya
University, Chikusa-ku, Nagoya 464-8603, JAPAN; telephone +81 52 789
3713; telefax +81 52 789 3703; e-mail h94m564m@eds.ecip.nagoya-u.ac.jp.
Key words: local density, quasiparticle states, t-t'-t"-J model.
Yuri Tavrin, Michael Siegel, and Johann Hinken, "Standard Method for
Detection of Magnetic Defects in Aircraft Engine Discs Using a HTS SQUID
Gradiometer." To be published in IEEE Trans. Appl. Supercond.: Proc.
of the 1998 Appl. Supercond. Conf. (ASC), Palm Desert, Calif., Sept. 13-
18, 1998. Institut fuer Schicht- und Ionentechnik (ISI),
Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY.
S. L. Thomasson and C. M. Gould, "Ultralow Temperature NMR Detection
Using dc Squids." To be published in Appl. Supercond. (in press).
Department of Physics and Astronomy, University of Southern California,
Los Angeles, CA 90089-0484.
Hiroki Tsuchiura, Yukio Tanaka, Masao Ogata, and Satoshi Kashiwaya,
"Impurity Effect in the Superconducting State of the Two-Dimensional t-J
Model." To be published in Physica C: Proc. of the First Crete
Euroconf. on Anomalous Complex Supercond. (ACS-1), Heraklion, Greece,
Sept. 25-Oct. 2, 1998. Contact Yukio Tanaka, CREST, Department of
Applied Physics, Nagoya University, Chikusa-ku, Nagoya 464-8603, JAPAN;
telephone +81 52 789 3713; telefax +81 52 789 3703; e-mail
h94m564m@eds.ecip.nagoya-u.ac.jp. Key words: two-dimensional t-J
model, Gutzwiller approximation, d-wave superconductivity, nonmagnetic
impurity, zero-energy peak.
G. A. Ummarino and R. S. Gonnelli, "Some Consequences of the Breakdown
of Migdal's Theorem in High-Tc Superconductors." To be published in
Physica C: Proc. of the First Crete Euroconf. on Anomalous Complex
Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct. 2, 1998.
Dipartimento di Fisica, INFM, Politecnico di Torino, I-10129 Torino,
ITALY; telefax +39 011 564 7399; e-mail gonelli@polito.it. Key words:
Migdal's theorem, coupling constant, Fermi energy. 74.50.+r.
P. Usak, "Measurement of the Transport Current Distribution in a
Superconducting Tape." To be published in Physica C (in press).
Institute of Electrical Engineering, Slovak Academy of Sciences, 84239
Bratislava, SLOVAKIA; telephone +421 7 5477 5816; telefax +421 7 5477
5826; e-mail elekusak@savba.sk. Key words: critical current, inverse
problem, current distribution.
W. Vodel, S. Nietzsche, H. Koch, and Glyscinski J. V. Zameck, "dc SQUID-
Based Position Detector for Gravitational Experiments." To be published
in Appl. Supercond. (in press). Institute of Solid State Physics,
Friedrich-Schiller-University Jena, Max-Wien-Platz 1, D-07743 Jena,
GERMANY.
Peter Woelfe, "Superfluid [3]^He and Unconventional Superconductors."
To be published in Physica C: Proc. of the First Crete Euroconf. on
Anomalous Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct.
2, 1998. Institut fuer Theorie der Kondensierten Materie, Universitaet
Karlsruhe, D-76128 Karlsruhe, GERMANY; telefax +49 721 698150; e-mail
rose@tkm.physik.uni-karlsruhe.de. Key words: superfluid,
superconductors, [3]^He.
R. Woerdenweber, "Growth of High-Tc Thin Film." To be published in
Supercond. Sci. & Technol. Institut fuer Schicht- und lonentechnik
(ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY.
Roger Woerdenweber, Jan Einfeld, Rolf Kutzner, Alexander G. Zaitsev,
Matthias A. Hein, Thomas Kaiser, and Guenter Mueller, "Large-Area YBCO
Films on Sapphire for Microwave Applications." To be published in IEEE
Trans. Appl. Supercond. Institut fuer Schicht- und lonentechnik (ISI),
Forschungszentrum Juelich GmbH, D-52425 Juelich, GERMANY.
J. Wosnitza, "Superconducting Properties of Quasi-Two-Dimensional
Organic Metals." To be published in Physica C: Proc. of the First
Crete Euroconf. on Anomalous Complex Supercond. (ACS-1), Heraklion,
Greece, Sept. 25-Oct. 2, 1998. Physikalisches Institut, Universitaet
Karlsruhe, D-76128 Karlsruhe, GERMANY; telephone +49 721 608 3515;
telefax +49 721 608 6103; e-mail jochen.wosnitza@physik.uni-
karlsruhe.de. Key words: superconductors, quasi-two-dimensional
organic metals, superconductors. 74.70.Kn; 74.60.-w.
Kouji Yasui and Takafumi Kita, "Quasiparticles of d-Wave Superconductors
in Finite Magnetic Fields." Department of Physics, Hokkaido University,
Sapporo 060-0810, JAPAN; Takafumi Kita's e-mail
kita@phys.sci.hokudai.ac.jp; preprint also available at
http://xxx.lanl.gov/abs/cond-mat/9905067.
H. R. Yi, Y. Zhang, H. Bousack, and A. I. Braginski, "High Frequency
Coupling Coefficient Between the Coplanar Resonator and Radio Frequency
SQUID." To be published in IEEE Trans. Appl. Supercond.: Proc. of the
1998 Appl. Supercond. Conf. (ASC), Palm Desert, Calif., Sept. 13-18,
1998. Institut fuer Festkoerperforschung, Forschungszentrum Juelich, D-
52425 Juelich, GERMANY; e-mail h.yi@fz-juelich.de.
S. Yu, S. M. Loureiro, and E. Takayama-Muromachi, "Critical Current
Densities of High-Tc Superconductors (Cu,Cr)Sr2Can-1CunO2n+3 (n=2,3)
Prepared Under High Pressure." To be published in Physica C (in press).
Contact E. Takayama-Muromachi, National Institute for Research in
Inorganic Materials (NIRIM), Namiki 1-1, Tsukuba, Ibaraki 305-0044,
JAPAN; telephone +81 298 58 5650; telefax +81 298 52 7449; e-mail
muromac@nirim.go.jp. Key words: high-Tc superconductor, magnetic
hysteresis, critical current densities, irreversibility field,
(Cu,Cr)Sr2Can-1CunO2n+3 (n=2,3).
Y. Zhang, D. F. He, N. Wolters, R. Otto, K. Barthels, X. H. Zeng, H. R.
Yi, H.-J. Krause, A. I. Braginski, and M. I. Faley, "Radio Frequency
Bias Current Scheme for dc Superconducting Quantum Interference Device."
To be published in IEEE Trans. Appl. Supercond. Institut fuer Schicht-
und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-52425 Juelich,
GERMANY.
Y. Zhang, H. R. Yi, J. Schubert, W. Zander, H.-J. Krause, H. Bousack,
and A. I. Braginski, "Operation of rf SQUID Magnetometers with a Multi-
Turn Flux Transformer Integrated with a Superconducting Labyrinth
Resonator." To be published in IEEE Trans. Appl. Supercond. Institut
fuer Schicht- und lonentechnik (ISI), Forschungszentrum Juelich GmbH, D-
52425 Juelich, GERMANY.
P. Zheng, Y. Q. Zhou, Z. J. Chen, S. Luo, W. H. Wang, Y. S. He, and J.
Duo, "The Vortex Glass to Liquid Transition in Bi2212 Whisker." To be
published in Physica C (in press). Cryogenic Laboratory, Chinese
Academy of Sciences, P.O. Box 2711, Beijing 100080, PEOPLE'S REPUBLIC OF
CHINA; telephone +86 10 6262 7683; telefax +86 10 6256 4049; e-mail
pzheng@cl.cryo.ac.cn. Key words: Bi2212 whisker, vortex glass-liquid
transition, critical exponent.
Marco Zoli, "Hopping Polaronic Motion in High-Tc Superconductors." To
be published in Physica C: Proc. of the First Crete Euroconf. on
Anomalous Complex Supercond. (ACS-1), Heraklion, Greece, Sept. 25-Oct.
2, 1998. Dipartimento di Matematica e Fisica, Istituto Nazionale di
Fisica della Materia, Universitadi Camerino, I-62032 Camerino, ITALY;
telefax +39 0737 40042; e-mail zoli@campus.unicam.it. Key words: high-
Tc superconductors, polarons, molecular crystal model.
F. Zygalsky, I. von Lampe, and S. Goetze, "Microbridge Preparation
Through Spincoating and Photolithography Without Etching." To be
published in Appl. Supercond. (in press). Institut fuer
Nichtmetallische, Werkstoffe Technische Universitaet Berlin, D-10587
Berlin, GERMANY.
COMING EVENTS
(An * indicates a previously listed event. Also see complete listing of
upcoming conferences and workshops at our Web site
http://www.iitap.iastate.edu/htcu/comevents.html.)
June 21 - 25, 1999: The European Conference Physics of Magnetism 99,
Science Centre of the Polish Academy of Sciences, Poznan, Poland. Ninth
conference in the series. Conference is intended to be an international
forum for the presentation and discussion of novel scientific ideas, in
a field of broadly understood magnetic phenomena, experimental results,
and new magnetic materials. Main objective is to bring together
scientists from Western, Central, and Eastern European countries
involved in research and application of new magnetic materials and high-
temperature superconductors. Special emphasis on novel metallic oxides
and anomalous magnetoresistive materials; low-dimensional quantum
magnets; heavy fermions, fluctuating valence, and Kondo systems; quantum
tunneling and magnetism in nanoscale; magnetic multilayers, surfaces,
and nanostructures; high-temperature superconductors; and electronic
structure. Plenary talks will be presented by invited distinguished
scientists from all over the world. Twenty-five plenary talks and about
200 oral and poster contributions. Proceedings will be published as a
special issue of Acta Physica Polonica. For information, contact Solid
State Theory Division, Institute of Physics, Adam Mickiewicz University,
Ul. Umultowska 85, 61-614 Poznan, Poland; telephone +48 61 8 273-041 or
-052; telefax +48 61 8 257-758; e-mail rom@alpha.amu.edu.pl or
mth@main.amu.edu.pl; Web site http://www.ifmpan. poznan.pl/zp2/main.htm.
Oct. 17 - 19, 1999: 12th International Symposium on Superconductivity
(ISSą99), Hotel Metro-politan Morioka, Morioka, Japan. Organized to
provide an opportunity for representatives from many countries to freely
exchange information, thereby contributing to the advancement of
superconductivity and strengthening international cooperation.
Symposium will consist of oral and poster sessions, highlighted by a few
dozen invited talks on the latest topics related to superconductivity.
Will cover the latest findings and related themes in the following
research fields of superconductivity: Physics and Chemistry -- theory,
physical properties, new measurement techniques, vortex physics and weak
links, new materials and syntheses, substitution, solid-state chemistry
and properties; Bulks -- processing, critical current, flux-pinning
mechanism, and standardization; Wires and Tapes -- processing, critical
current, and standardization; System Applications -- power,
transportation, magnet, magnetic shield, and others; Films and Junctions
-- processing, properties, lithography, junction fabrication, physics
and standardization; Electronics -- digital, analog, SQUID, and other
electronics devices using HTS and LTS materials. Abstract deadline,
June 30, 1999. Official language is English. For information, contact
ISTEC, Eishin Kaihatsu Bldg. 6F, 34-3 Shimbashi 5-chome, Minato-ku,
Tokyo 105-0004, Japan; telephone +81 3 3431 4002; telefax +81 3 3431
4044. Or contact Japan Convention Services, Inc., Nippon Press Center,
Bldg. 4F, 2-2-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-0011, Japan;
telephone +81 3 3508 1213; telefax +81 3 3508 0820.
High-Tc Update is the high-Tc superconductivity information exchange
newsletter. Please send 1) preprints, reprints, and other research
reports; 2) descriptions of on-going work; 3) meeting announcements and
summaries.
The information contained herein is intended for limited distribution.
Readers are expected to respect the rights of the authors.
Please address all contributions and inquiries to:
Dr. Sreeparna Mitra, A219 Physics
Ames Laboratory/Iowa State University
Ames, Iowa 50011-3020
Telephone: (515) 294-3877 Telefax: (515) 294-1134
E-mail: MITRA@AMESLAB.GOV
or MITRA@IASTATE.EDU
Project Director/Editor: Sreeparna Mitra
Science Editor: John R. Clem
High-Tc Update, Vol. 13, #12, June 15, 1999.