Magnetic properties of single crystal EuCoAs
Jared Ballinger, Lowell E. Wenger, Yogesh K. Vohra, and Athena S. Sefat
Magnetization measurements at ambient pressure have been performed on single crystal EuCoAs, a compound having a similar crystalline structure as the pressure-induced EuFeAs superconductor. Similar to the magnetic characteristics of EuFeAs at ambient pressure, the effective paramagnetic moment at hi ... [J. Appl. Phys. 111, 07E106 (2012)] published Mon Feb 13, 2012.
Indications of an Electronic Phase Transition in Two-Dimensional Superconducting YBaCuO Thin Films Induced by Electrostatic Doping
Xiang Leng, Javier Garcia-Barriocanal, Boyi Yang, Yeonbae Lee, J. Kinney et al.
We successfully tuned an underdoped ultrathin YBaCuO film into the overdoped regime by means of electrostatic doping using an ionic liquid as a dielectric material. This process proved to be reversible. Transport measurements showed a series of anomalous features compared to chemically doped bulk sa ... [Phys. Rev. Lett. 108, 067004 ] published .
Fluctuation-induced conductivity analyses of Be-doped (BiCuLiTl)BaCaCuO superconductors in the critical regime and beyond
Nawazish A. Khan, Qurat-ul-Ain, Umber Firdous, and Shaheryar
We have successfully synthesized (BiCuLiTl)BaCaCuO and (BiCuLiTl)Ba(CaBe)CuO samples and studied their excess conductivity analyses (fluctuation-induced conductivity) of resistivity data. The main objective of such analyses is to investigate the influence of Be-substitution on the superconductivity ... [J. Appl. Phys. 111, 033917 (2012)] published Fri Feb 10, 2012.
Tantalum nitride superconducting single-photon detectors with low cut-off energy
A. Engel, A. Aeschbacher, K. Inderbitzin, A. Schilling, K. Il'in et al.
Materials with a small superconducting energy gap are expected to favor a high detection efficiency of low-energy photons in superconducting nanowire single-photon detectors. We developed a TaN detector with smaller gap and lower density of states at the Fermi energy than in comparable NbN devices, ... [Appl. Phys. Lett. 100, 062601 (2012)] published Fri Feb 10, 2012.
Reconstructing the bulk Fermi surface and superconducting gap properties from neutron scattering experiments
Tanmoy Das, R. S. Markiewicz, and A. Bansil
We develop an analytical tool to extract bulk electronic properties of unconventional superconductors from inelastic neutron scattering spectra. We show that the upward and downward branches of the spin excitation spectra have distinct origins, with the upper branch representing a gapped spin-wave d ... [Phys. Rev. B 85, 064510 ] published .
Magnetic-field tuned anisotropy in superconducting RbFeSe
S. Bosma, R. Puzniak, A. Krzton-Maziopa, M. Bendele, E. Pomjakushina et al.
The anisotropic superconducting properties of a RbFeSe single crystal with T~=32 K were investigated by means of superconducting quantum interference device (SQUID) and torque magnetometry, probing the effective magnetic penetration depth lambda and the magnetic penetration depth anisotropy gamma. I ... [Phys. Rev. B 85, 064509 ] published .
Imaging of magnetic flux distribution in vicinity of insulating particles in high-T superconductor by electron holography
Zentaro Akase, Hiroto Kasai, Shuichi Mamishin, Daisuke Shindo, Mitsuru Morita et al.
REBaCuO (RE: rare earth) bulk superconductors, whose microstructures can be controlled by quench and melt growth (QMG) processing, have a high critical current density J, which makes them well suited for use in practical applications. Through a combination of electron holography and a focused ion-be ... [J. Appl. Phys. 111, 033912 (2012)] published Thu Feb 9, 2012.
Quantum Order-by-Disorder Near Criticality and the Secret of Partial Order in MnSi
Frank Kruger, Una Karahasanovic, and Andrew G. Green
The vicinity of quantum phase transitions has proven fertile ground in the search for new quantum phases. We propose a physically motivated and unifying description of phase reconstruction near metallic quantum-critical points using the idea of quantum order by disorder. Certain deformations of the ... [Phys. Rev. Lett. 108, 067003 ] published .
Manifestly Non-Gaussian Fluctuations in Superconductor-Normal Metal Tunnel Nanostructures
M. A. Laakso, T. T. Heikkila, and Yuli V. Nazarov
We propose a mesoscopic setup which exhibits strong and manifestly non-Gaussian fluctuations of energy and temperature when suitably driven out of equilibrium. The setup consists of a normal metal island (N) coupled by tunnel junctions (I) to two superconducting leads (S), forming a SINIS structure, ... [Phys. Rev. Lett. 108, 067002 ] published .
Avoidance of Majorana Resonances in Periodic Topological Superconductor-Nanowire Structures
Jay D. Sau, Chien Hung Lin, Hoi-Yin Hui, and S. Das Sarma
Semiconducting nanowires in proximity to superconductors are promising experimental systems for Majorana fermions which may ultimately be used as building blocks for topological quantum computers. A serious challenge in the experimental realization of the Majorana fermion in these semiconductor-supe ... [Phys. Rev. Lett. 108, 067001 ] published .
Velocity-induced reorientation of a fast driven Abrikosov lattice
S. Okuma, D. Shimamoto, and N. Kokubo
From mode-locking measurements where the vortex lattice is driven quickly by superimposed dc and ac currents, we find a velocity-induced rotation of lattice orientation from a perpendicular to a parallel orientation. This is a dynamic transition caused by increased velocity. At the threshold of the ... [Phys. Rev. B 85, 064508 ] published .
Ab initio investigations of phonons and superconductivity in the cubic Laves structures LaAl and YAl
S. Duman and H. M. Tutuncu
We have performed an ab initio study of structural, elastic, electronic, lattice-dynamical, and electron-phonon interaction properties of the cubic Laves structures LaAl and YAl. The calculations have been carried out within the density-functional theory and linear response formalism using pseudopot ... [J. Appl. Phys. 111, 033514 (2012)] published Wed Feb 8, 2012.
Magnetic field dependence of the quantum tunneling of normal-superconductor interfaces in a type-I Pb superconductor
Saul Velez, Ricardo Zarzuela, Antoni Garcia-Santiago, and Javier Tejada
We report experimental evidence of the effect of an applied magnetic field on the nonthermal magnetic relaxation in a disk-shaped type-I lead superconductor. The time evolution of the irreversible magnetization proves to be logarithmic for a wide range of temperatures and magnetic field values along ... [Phys. Rev. B 85, 064506 ] published .
Domain structure and magnetic pinning in ferromagnetic/superconducting hybrids
V. Vlasko-Vlasov, A. Buzdin, A. Melnikov, U. Welp, D. Rosenmann et al.
Magnetic patterns in three iron-garnet films with different magnetic properties covered with 100-nm superconducting Nb film are studied using a magneto-optical imaging technique. In all samples the strong coupling between ferromagnetic domains and vortices noticeably modifies the magnetization proce ... [Phys. Rev. B 85, 064505 ] published .
Coexisting pseudogap, charge-transfer-gap, and Mott-gap energy scales in the resonant inelastic x-ray scattering spectra of electron-doped cuprate superconductors
Susmita Basak, Tanmoy Das, Hsin Lin, M. Z. Hasan, R. S. Markiewicz et al.
We present a computation of Cu K-edge resonant inelastic x-ray scattering (RIXS) spectra for electron-doped cuprates, which includes coupling to bosonic fluctuations. Comparison with experiment over a wide range of energy and momentum transfers allows us to identify the signatures of three key norma ... [Phys. Rev. B 85, 075104 ] published .
Structure of the oxygen-annealed chalcogenide superconductor FeTeSeO
Hefei Hu, Jian-Min Zuo, Mao Zheng, James N. Eckstein, Wan Kyu Park et al.
The as-grown single crystal FeTeSe with the tetragonal PbO-type structure is nonsuperconducting owing to the excess Fe. Superconductivity is induced after oxygen annealing with an onset and zero resistance transition temperature around 14.5 K and 11.5 K, respectively. The oxygen doping is evidenced ... [Phys. Rev. B 85, 064504 ] published .
Mechanical properties of highly oriented FeSeTe superconductor
Jorge Luiz Pimentel Junior, Paulo Pureur, Cristiano Santos Lopes, Francisco Carlos Serbena, Carlos Eugenio Foerster et al.
We have synthesized highly oriented samples of the superconducting compound FeSeTe and investigated its mechanical properties. These samples were characterized by scanning electron microscopy (SEM) with energy-dispersive analysis, x-ray diffraction, and electrical resistivity. The measured critical ... [J. Appl. Phys. 111, 033908 (2012)] published Mon Feb 6, 2012.
Superconductivity in the vicinity of ferromagnetism in oxygen free perovskite MgCNi: An experimental and density functional theory study
Anuj Kumar, Rajveer Jha, Shiva Kumar Singh, Jagdish Kumar, P. K. Ahluwalia et al.
We report synthesis, structural, magnetic, specific heat, and density functional theory (DFT) studies on the MgCNi superconductor. Polycrystalline MgCNi samples are synthesized through the standard solid state reaction route and found to crystallize in the cubic perovskite structure with space group ... [J. Appl. Phys. 111, 033907 (2012)] published Mon Feb 6, 2012.
Regimes of flux transport at microwave frequencies in nanostructured high-T films
R. Wordenweber, E. Hollmann, J. Schubert, R. Kutzner, and G. Panaitov
We report on combined dc and microwave electronic measurements of magnetic flux transport in micron and submicron-patterned high-T films. In a given temperature regime below the superconducting transition temperature T, the current-driven flux transport is restricted to flux motion guided by the sub ... [Phys. Rev. B 85, 064503 ] published .
Complex mixed state of the Pauli-limited superconductor CeCoIn
X. Gratens, L. Mendonca-Ferreira, Y. Kopelevich, N. F. Oliveira, Jr., R. R. Urbano et al.
Magnetization measurements were performed on CeCoIn at temperatures down to 20 mK and magnetic fields up to 17 T applied along different crystallographic orientations. For field configurations nearly parallel to the ab plane (theta<~40 and T<=50 mK), we have found an intriguing vortex dynamics regi ... [Phys. Rev. B 85, 054502 ] published .
Correlation between the interlayer Josephson coupling strength and an enhanced superconducting transition temperature of multilayer cuprate superconductors
Y. Hirata, K. M. Kojima, M. Ishikado, S. Uchida, A. Iyo et al.
Infrared reflectivity spectra of multilayered HgBaCaCuO (n=2, 3, 4, and 5) are measured. Optical plasma modes associated with the Josephson coupling between CuO planes within a multilayer appear below T in the c-axis component of the reflectivity spectrum. The result allows for quantitative estimati ... [Phys. Rev. B 85, 054501 ] published .
A perspective of superconductivity as multiband phenomena: Cuprate, iron and aromatic systems. (arXiv:1202.2170v1 [cond-mat.supr-con])
ePrint arXiv http://arXiv.org/
Influence of the interplay between de Gennes boundary conditions and cubicity of Ginzburg-Landau equation on the properties of superconducting films. (arXiv:1202.2322v1 [cond-mat.mes-hall])
ePrint arXiv http://arXiv.org/
Signatures of Majorana Fermions in Hybrid Superconductor-Topological Insulator Devices. (arXiv:1202.2323v1 [cond-mat.mes-hall])
ePrint arXiv http://arXiv.org/
A dynamical study of phase fluctuations and their critical slowing down in amorphous superconducting films. (arXiv:1010.2996v4 [cond-mat.supr-con] UPDATED)
ePrint arXiv http://arXiv.org/
Majorana resonances and how to avoid them in periodic topological superconductor-nanowire structures. (arXiv:1103.2770v2 [cond-mat.supr-con] UPDATED)
ePrint arXiv http://arXiv.org/
Tantalum nitride superconducting single-photon detectors with low cut-off energy. (arXiv:1110.4576v3 [cond-mat.supr-con] UPDATED)
ePrint arXiv http://arXiv.org/