Thermodynamic properties of Pb determined from pressure-dependent critical-field measurements
N. Suresh and J. L. Tallon
We have carried out extensive low-temperature (1.510 K) measurements of the critical field H[sub c] for the element Pb up to a pressure of P=1.2 GPa. From these data, the electronic entropy, specific heat, thermal-expansion coefficient, and compressibility are calculated as a function of temperatu ... [Phys. Rev. B 75, 174502 (2007)] published Thu May 3, 2007.
Properties of vortex propagation in a niobium film with spacing-graded density of pinning sites
Lance Horng, T. C. Wu, J. C. Wu, R. Cao, and T. J. Yang
The vortex propagation has been investigated in Nb superconductors with one dimension spacing-graded density of submicrometer-scaled holes in this research. A rectification effect can be discerned because the applied ac is transformed into a net dc voltage. These results demonstrate that the rectifi ... [J. Appl. Phys. 101, 09G113 (2007)] published Thu May 3, 2007.
Layered superconductors as nonlinear waveguides for terahertz waves
Sergey Savel'ev, V. A. Yampol'skii, A. L. Rakhmanov, and Franco Nori
We show that unusual nonlinear self-sustained waves, called nonlinear waveguide modes (NWGMs), can propagate along thin slabs of layered superconductors. We show that these waves are stable in the main approximation for extremely anisotropic superconductors if the nonlinear wave amplitude is smaller ... [Phys. Rev. B 75, 184503 (2007)] published Wed May 2, 2007.
Stray-fields-based magnetoresistance mechanism in Ni[sub 80]Fe[sub 20]-Nb-Ni[sub 80]Fe[sub 20] trilayered hybrids
D. Stamopoulos, E. Manios, and M. Pissas
We report on the transport and magnetic properties of hybrid trilayers (TL's) and bilayers (BL's) that consist of low spin-polarized Ni[sub 80]Fe[sub 20] exhibiting in-plane but no uniaxial anisotropy and low-T[sub c] Nb. We reveal a magnetoresistance effect of magnitude identical to the ones that w ... [Phys. Rev. B 75, 184504 (2007)] published Wed May 2, 2007.
Theory of tunneling spectroscopy in UPd[sub 2]Al[sub 3]
David Parker and Peter Thalmeier
There is still significant debate about the symmetry of the order parameter in the heavy-fermion superconductor UPd[sub 2]Al[sub 3], with proposals for cos(k[sub 3]), cos(2k[sub 3]), sin(k[sub 3]), and e[sup iphi] sin(k[sub 3]). Here, we analyze the tunneling spectroscopy of this compound and demon ... [Phys. Rev. B 75, 184502 (2007)] published Wed May 2, 2007.
Structural modification of twin boundaries in YBa[sub 2]Cu[sub 3]O[sub 6 + eta] oxides: Effects of oxygen concentration and temperature
Qingping Meng and Yimei Zhu
The modification of the twin boundaries in YBa[sub 2]Cu[sub 3]O[sub 6+eta] due to the oxygen ordering below the temperature of the tetragonal-orthorhombic phase transformation has been studied using mean field theory and spatial gradient terms for the oxygen concentration variation. The distribution ... [Phys. Rev. B 75, 174501 (2007)] published Wed May 2, 2007.
Nonlinear magnetic response from the Ru[sub 0.9]Sr[sub 2]YCu[sub 2.1]O[sub 7.9] magnetosuperconductor and its resultant phase separation
I. Živković, V. P. S. Awana, H. Kishan, S. Balamurugan, E. Takayama-Muromachi et al.
We investigated the third harmonic nonlinear susceptibility of the Ru[sub 0.9]Sr[sub 2]YCu[sub 2.1]O[sub 7.9] magnetosuperconductor and found the presence of two well separated negative peaks. The peak at T[sub M]=140 K is connected to the previously well known main magnetic ordering of the Ru subl ... [J. Appl. Phys. 101, 09G112 (2007)] published Wed May 2, 2007.
Superconductivity in zero-dimensional indium nanoparticles
F.-Y. Wu, C. C. Yang, C.-M. Wu, C.-W. Wang, and W.-H. Li
An In nanoparticle powder was fabricated by employing the thermal evaporation method. Size analysis using x-ray diffraction profiles analysis and atomic force microscopy images indicates an average particle diameter of 36(2) nm and a Gaussian size distribution with a half-width of 3 nm. The superc ... [J. Appl. Phys. 101, 09G111 (2007)] published Wed May 2, 2007.
Elasticity and Melting of Skyrmion Flux Lattices in p-Wave Superconductors
Qi Li, John Toner, and D. Belitz
We analytically calculate the energy, magnetization curves [B(H)], and elasticity of Skyrmions flux lattices in p-wave superconductors near the lower critical field H[sub c1], and we use these results with the Lindemann criterion to predict their melting curve. In striking contrast to vortex flux la ... [Phys. Rev. Lett. 98, 187002 (2007)] published Wed May 2, 2007.
Specific heat and anisotropy of the nonconventional superconductors PuCoGa[sub 5] and PuRhGa[sub 5]
P. Javorsky, E. Colineau, F. Wastin, F. Jutier, J.-C. Griveau et al.
We report on specific-heat measurements under a magnetic field on oriented single crystals of the nonconventional superconductors PuCoGa[sub 5] and PuRhGa[sub 5] with superconducting transition temperature T[sub c]~18 and 9 K, respectively. In the superconducting state, the electronic specific heat ... [Phys. Rev. B 75, 184501 (2007)] published Tue May 1, 2007.
Sharp Superconductor-Insulator Transition in Short Wires
Dganit Meidan, Yuval Oreg, and Gil Refael
Recent experiments on short MoGe nanowires show a sharp superconducting-insulating transition at the universal resistance R[sub Q]=h/(4e[sup 2]), contrary to the expectation of a smooth temperature dependence of the resistance for such Josephson-like systems. We present a self-consistent renormaliza ... [Phys. Rev. Lett. 98, 187001 (2007)] published Tue May 1, 2007.
Temperature-dependent matching in a flux-line lattice interacting with a triangular array of pinning centers without long-range order
J. Eisenmenger, M. Oettinger, C. Pfahler, A. Plettl, P. Walther et al.
A triangular array of nanoscaled artificial pinning centers (APCs) for magnetic flux lines is prepared into a Nb thin film. The APCs are formed by deposition of Nb onto a Si substrate covered with nanopillars with diameters of 20 nm and lattice constant a=122 nm. The production of pillars is based ... [Phys. Rev. B 75, 144514 (2007)] published Mon Apr 30, 2007.
Long-wavelength dispersion of transverse acoustic phonons in untwinned YBa[sub 2]Cu[sub 3]O[sub 7 - delta] single crystals
Andrea Gauzzi, Matteo d'Astuto, Francesca Licci, Alexei Bossak, and Michael Krisch
In order to study the possibility of enhancing the electron-phonon coupling lambda in cuprates by soft transverse acoustic (TA) modes, using high-resolution (DeltaE=1.3 meV) inelastic x-ray scattering, we measured the in-plane TA mode at low q<~0.1 along the a[sup *] axis on optimally doped untwinn ... [Phys. Rev. B 75, 144511 (2007)] published Mon Apr 30, 2007.
Phase diagram of vortices in high-T[sub c] superconductors from lattice defect model with pinning
Jurgen Dietel and Hagen Kleinert
The theory presented is based on a simple Hamiltonian for a vortex lattice in a weak impurity background which includes linear elasticity and plasticity, the latter in the form of integer valued fields accounting for defects. Within a quadratic approximation in the impurity potential, we find a firs ... [Phys. Rev. B 75, 144513 (2007)] published Mon Apr 30, 2007.
Antiferromagnetism in two-dimensional t-J model: A pseudospin representation
Daisuke Yamamoto and Susumu Kurihara
We discuss a pseudospin representation of the two-dimensional t-J model. We introduce pseudospins associated with empty sites, deriving a representation of the t-J model that consists of local spins and spinless fermions. We show, within a mean-field approximation, that our representation of t-J mod ... [Phys. Rev. B 75, 134520 (2007)] published Mon Apr 30, 2007.
Manipulation of the vortex motion in nanostructured ferromagnetic/superconductor hybrids
A. V. Silhanek, W. Gillijns, V. V. Moshchalkov, V. Metlushko, F. Gozzini et al.
The authors investigate the rectified motion of vortices in superconducting films deposited on top of a close-packed array of open in-plane magnetized triangular micromagnets. The dc voltage induced by the vortex drift under an ac excitation is recorded for three different magnetic configurations of ... [Appl. Phys. Lett. 90, 182501 (2007)] published Mon Apr 30, 2007.
Effects of local artificial defects in multifilamentary coated conductors with patterned links
C. Kwon, J. L. Young, R. G. James, George A. Levin, Timothy J. Haugan et al.
Multifilamentary coated conductor (MFCC) samples with patterned links have been studied using transport and scanning laser microscopy (SLM) techniques. Striation patterns are fashioned to define multiple filaments with discretely placed superconducting (SC) links between the filaments for current sh ... [J. Appl. Phys. 101, 083908 (2007)] published Mon Apr 30, 2007.
Antiferromagnetism and superconductivity: Cuprate plane magnetic ordering in YSr[sub 2]Cu[sub 2.1]Nb[sub 0.9]O[sub 8 - delta]
H. A. Blackstead, W. B. Yelon, M. Kornecki, M. P. Smylie, Q. Cai et al.
YSr[sub 2]Cu[sub 2.1]Nb[sub 0.9]O[sub 8delta], prepared using a high-pressure, high-temperature process, has been studied using superconducting quantum interference device magnetometry, neutron diffraction, and electron spin resonance (ESR). This material, in which Cu is the only magnetic ion, shows ... [Phys. Rev. B 75, 140514 (2007)] published Fri Apr 27, 2007.
Small-angle neutron scattering measurements of the vortex lattice in CaC[sub 6]
R. Cubitt, J. S. White, M. Laver, M. R. Eskildsen, C. D. Dewhurst et al.
Small-angle neutron scattering has been applied to study the vortex lattice in the intercalated graphite superconductor CaC[sub 6] (T[sub c]=11.3 K). Scattering from the vortex lattice is in the form of a ring, most likely reflecting the absence of in-plane orientational order of the pyrolitic grap ... [Phys. Rev. B 75, 140516 (2007)] published Fri Apr 27, 2007.
Spin susceptibility representation of the pairing interaction for the two-dimensional Hubbard model
T. A. Maier, M. Jarrell, and D. J. Scalapino
Using numerical dynamic cluster quantum Monte Carlo results, we study a simple approximation for the pairing interaction of a two-dimensional Hubbard model with an on-site Coulomb interaction U equal to the bandwidth. We find that with an effective temperature-dependent coupling [overline U](T) and ... [Phys. Rev. B 75, 134519 (2007)] published Fri Apr 27, 2007.
Underdoped cuprate phenomenology in the two-dimensional Hubbard model within the composite operator method
Adolfo Avella and Ferdinando Mancini
The two-dimensional Hubbard model is studied within the composite operator method (COM) with the self-energy computed in the self-consistent Born approximation (SCBA). The COM describes interacting electrons in terms of the new elementary excitations that appear in the system owing to strong correla ... [Phys. Rev. B 75, 134518 (2007)] published Fri Apr 27, 2007.
Using inhomogeneity to raise the superconducting critical temperature in a two-dimensional XY model
Y. L. Loh and E. W. Carlson
Superconductors with low superfluid density are often dominated by phase fluctuations of the order parameter. In this regime, their physics may be described by XY models. The transition temperature T[sub c] of such models is of the same order as the zero-temperature phase stiffness (helicity modulus ... [Phys. Rev. B 75, 132506 (2007)] published Fri Apr 27, 2007.
AC Magnetic Susceptibility Of Elements In Ag Sheathed BSCCO (2223) Tapes With Te Addition
A. Stoyanova-Ivanova, S. Terzieva, V. Mihailov, V. Mikli, and V. Kovachev
The Ag sheathed tapes with nominals Bi[sub 1.8]Pb[sub 0.4]Sr[sub 2]Ca[sub 2.2]Cu[sub 3.2]O[sub 10+y] and Bi[sub 1.6]Pb[sub 0.3]Te[sub 0.1]Sr[sub 2]Ca[sub 3]Cu[sub 4]O[sub 10+y] obtained by OPIT method were examined. Temperature dependence of AC magnetic susceptibility (chi[prime] and chi[double-prim ... [AIP Conf. Proc. 899, 802 (2007)] published Fri Apr 27, 2007.
HTS/Manganite Double Layer Structures
T. Nurgaliev, S. Miteva, B. Blagoev, E. Mateev, L. Neshkov et al.
Superconductor/ferromagnetic Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7delta]/La[sub 0.7]Sr[sub 0.3]MnO[sub 3] (YBCO/LSMO) structures were prepared and the parameters of YBCO films in these structures were investigated at 77 K. The results were interpreted as due to a modification of the electric characteris ... [AIP Conf. Proc. 899, 788 (2007)] published Fri Apr 27, 2007.
Nonvacuum Deposition of Silver Doped YBCO Coated Conductor on %100 Lattice Match Buffered Ni Tapes
L. Arda, O. Cakiroglu, S. Keskin, and O. A. Sacli
Silver doped YBa[sub 2]Cu[sub 3]O[sub 7delta] (YBCO) coated conductors were fabricated on Gd[sub 1.624]Ho[sub 0.376]O[sub 3] (100 % lattice match with YBCO) textured buffer layers on Ni tape by reel-to-reel sol-gel dip coating system. Sample were prepared with different wt(15) % Ag doped ratio. The ... [AIP Conf. Proc. 899, 767 (2007)] published Fri Apr 27, 2007.
Dependence of Josephson Junction Critical Current on The Deposition Rate of YBa[sub 2]Cu[sub 3]O[sub 7 - delta ] Thin Films
B. P. Algul, I. Avci, R. Akram, A. Bozbey, M. Tepe et al.
We have reported the effect of YBa[sub 2]Cu[sub 3]O[sub 7delta] (YBCO) thin film deposition rate on the 24 and 30 degree STO bicrystal Josephson junctions critical currents by fabricating series of junctions with different deposition rates. Dependence of YBCO thin film structures on the deposition r ... [AIP Conf. Proc. 899, 762 (2007)] published Fri Apr 27, 2007.
On the Anomalous Microwave Power Dependency of both Non-Resonant and Cu[sup 2 + ] Resonant Microwave Absorption in a YBa[sub 2]Cu[sub 3]O[sub 7 - delta ] Type Superconductor
M. Velter-Stefanescu and O. G. Duliu
A ceramic high temperature superconductor [HTS] of Y-Ba-Cu-O type has been investigated at 77 K by using a standard X-band Electron Paramagnetic Resonance (EPR) configuration. At very low microwave power (< 1 mW) the non-resonant or zero field signal (ZFS) was in phase with DPPH signal, pleading for ... [AIP Conf. Proc. 899, 668 (2007)] published Fri Apr 27, 2007.
Crystallographic Study of Mixtures La[sub 1 + x]Ba[sub 2 - x]Cu[sub 3]O[sub y] (x = 0,0.2,0.4,0.6) after annealing at 860[degree]C
A. Stergiou, S. Yilmaz, and C. Stergiou
Four powder mixtures with chemical formula La[sub 1+x]Ba[sub 2x]Cu[sub 3]O[sub y] was prepared. The mixtures were heated in free atmosphere, at temperature 850 degrees C for 60h and then at 860 degrees C for 40h. XRD measurements were obtained with CuKa radiation. The samples were characterized with ... [AIP Conf. Proc. 899, 657 (2007)] published Fri Apr 27, 2007.
Josephson Coupling Through Ferromagnetic Bilayer With Non-collinear Magnetizations
Z. Pajović, M. Božović, Z. Radović, J. Cayssol, and A. Buzdin
We study the Josephson effect in clean heterojunctions consisting of ferromagnetic bilayer between superconductors. We solve the scattering problem based on the Bogoliubov-de Gennes equation for any relative orientation of in-plane magnetizations, arbitrary transparency of interfaces, and mismatch o ... [AIP Conf. Proc. 899, 637 (2007)] published Fri Apr 27, 2007.
Thermal conductivity in the vortex state of s-wave and d-wave superconductors
P. Miranović, H. Adachi, M. Ichioka, and K. Machida
Thermal conductivity in the vortex state has been calculated by solving self-consistently Eilenberger quasi-classical equations of superconductivity. Field dependence of thermal conductivity tensor has been calculated for various impurity parameters. We showed the difference in the field dependence ... [AIP Conf. Proc. 899, 630 (2007)] published Fri Apr 27, 2007.
Anomalous Suppression of Bi2212 Superconductivity in Bi[sub 1.8]Pb[sub 0.4]Sr[sub 2]Ca[sub 2 - x]Y[sub x]Cu[sub 3 - y]Zn[sub y]O[sub w] Samples
Phase V. Mihalache and G. Aldica
AC-susceptibility vs temperature measurements performed on (Bi,Pb)[sub 2]Sr[sub 2]Ca[sub 1x]Y[sub x]Cu[sub 2y]Zn[sub y]O[sub z] phase present in sintered Bi[sub 1.8]Pb[sub 0.4]Sr[sub 2]Ca[sub 2x]Y[sub x]Cu[sub 3y]Zn[sub y]O[sub w] polycrystalline samples, 0 <= x <= 0.45 and y = 0 and 0.03. We report ... [AIP Conf. Proc. 899, 628 (2007)] published Fri Apr 27, 2007.
Superconducting, Magnetic and Transport Properties of RuSr[sub 2]R[sub 1.4]Ce[sub 0.6]Cu[sub 2]O[sub 10 - delta ] (R = Eu, Sm)
N. Balchev, K. Nenkov, G. Mihova, and J. Pirov
... [AIP Conf. Proc. 899, 584 (2007)] published Fri Apr 27, 2007.
Irreversible Magnetization above Critical Temperature in Superconducting Y[sub 0.47]Pr[sub 0.53]Ba[sub 2]Cu[sub 3]O[sub 7 - delta ]
V. Sandu, P. Gyawali, T. Katuwal, C. C. Amasan, B. J. Taylor et al.
Using magnetization measurements, we report the existence of an irreversibility in the magnetization in Y[sub 0.47]Pr[sub 0.53]Ba[sub 2]Cu[sub 3]O[sub 7delta] single crystals above the critical temperature (T[sub c] = 13 K) that is visible up to 200 K. Magnetization in temperature displays irreversi ... [AIP Conf. Proc. 899, 279 (2007)] published Fri Apr 27, 2007.
Vortex Dynamics In case of Possible Room Temperature Superconductivity
Sahin Aktas and Selcuk Haciomeroglu
Two-dimensional temperature dependent vortex dynamics has been studied by Monte-Carlo method. At low temperatures far below T[sub C], well known phase transition from glassy state to vortex liquid state known as melting has been obtained. Assuming the possible future existence of real high temperatu ... [AIP Conf. Proc. 899, 277 (2007)] published Fri Apr 27, 2007.
Correlation Between The Anisotropy and The Effective Mass of The Quasi-Particles in Oxide Superconductors
Ozden Aslan, Zeynep Guven Ozdemir, and Ulker Onbasli
Determination of Josephson penetration depth has a crucial importance in calculation of both anisotropy factor and the effective mass of quasi-particles (m[sup *]) in high temperature copper oxide superconductors. In this study, the effective mass values of the quasi-particles have been determined v ... [AIP Conf. Proc. 899, 271 (2007)] published Fri Apr 27, 2007.
Electron Doping of Cuprates via Interfaces with Manganites. [arXiv:0705.0498v1]
ePrint arXiv http://arXiv.org/
Thermalized non-equilibrated matter and high temperature superconducting state in quantum many-body systems. [arXiv:0705.0509v1]
ePrint arXiv http://arXiv.org/
Superconductivity in epitaxial thin films of NaxCoO2 y D2O. [arXiv:0705.0517v1]
ePrint arXiv http://arXiv.org/
One-Particle Anomalous Excitations of Gutzwiller Projected BCS Superconductors and Bogoliubov Quasi-Particle Characteristics. [arXiv:cond-mat/0610444v2 UPDATED]
ePrint arXiv http://arXiv.org/
Continuously Tunable Charge in Andreev Quantum Dots. [arXiv:cond-mat/0610180v2 UPDATED]
ePrint arXiv http://arXiv.org/
Multi-Higgs U(1) Lattice Gauge Theory in Three Dimensions. [arXiv:0704.1323v2 UPDATED]
ePrint arXiv http://arXiv.org/
Charge transfer mechanism and Tc(x) dependence in Y0.8(Ca)0.2Ba2Cu3O6+x. [arXiv:0705.0299v2 UPDATED]
ePrint arXiv http://arXiv.org/
Photo-assisted Andreev reflection as a probe of quantum noise. [arXiv:cond-mat/0602408v2 UPDATED]
ePrint arXiv http://arXiv.org/
Unmasking the nodal quasiparticle dynamics in cuprate superconductors using low-energy photoemission. [arXiv:cond-mat/0603006v2 UPDATED]
ePrint arXiv http://arXiv.org/
Criterion for dynamical chiral symmetry breaking. [arXiv:hep-th/0703050v3 UPDATED]
ePrint arXiv http://arXiv.org/