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Related papers: MgB2: superconductivity and pressure effects

200 papers

Consistent account is provided of strongly anisotropic properties in thermodynamics of MgB$_2$ under magnetic field $H$ using approximate analytic solution in the quasiclassical formalism. With the strength of the pairing interactions and…

Superconductivity · Physics 2009-11-10 Masatoshi Mugikura , Hiroaki Kusunose , Yoshio Kuramoto

We investigate the upper critical field in a dirty two-band superconductor within quasiclassical Usadel equations. The regime of very high anisotropy in the quasi-2D band, relevant for MgB$_{2}$, is considered. We show that strong…

Superconductivity · Physics 2009-11-10 A. A. Golubov , A. E. Koshelev

This article is a review o over theory of superconductivity, which is constructed for systems with two overlapping energy bands at the Fermi surface and with arbitrary charge carrier density.There is taken into account all possible kinds of…

Superconductivity · Physics 2007-05-23 M. E. Palistrant

The possibility is indicated of applying the theory of superconductors with overlapping energy bands to describe the thermodynamic and electromagnetic properties of the high-temperature compounds $La_{2-x}(Ba,Sr)_xCuO_4$ and…

Superconductivity · Physics 2007-05-23 V. A. Moskalenko , M. E. Palistrant , V. M. Vakalyuk

MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…

Superconductivity · Physics 2009-11-07 A. Plecenik , S. Benacka , P. Kus , M. Grajcar

We investigated carbon substitution effect on boron plane of superconducting MgB$_2$. MgB$_2$ and MgB$_{1.8}$C$_{0.2}$ samples are synthesized under high pressure furnace. MgB$_{1.8}$C$_{0.2}$ are characterized as AlB$_2$-type single phase…

Superconductivity · Physics 2007-05-23 Jai Seok Ahn , Eun Jip Choi

We have measured the Raman spectra of polycrystalline MgB$_{2}$ from 25 {\cm} to 1200 {\cm}. When the temperature was decreased below the superconducting transition temperature $T_c$, we observed a superconductivity-induced redistribution…

Superconductivity · Physics 2016-08-31 X. K. Chen , M. J. Konstantinovic , J. C. Irwin , D. D. Lawrie , J. P. Franck

Thermal conductivity of superconducting MgB2 was studied in both the superconducting and the normal state region. The latter is almost equally determined by the electronic - and the lattice contribution to the total thermal conductivity. In…

Superconductivity · Physics 2007-05-23 E. Bauer , Ch. Paul , St. Berger , S. Majumdar , H. Michor , M. Giovannini , A. Saccone , A. Bianconi

A series of calculations on MgB2 and related isoelectronic systems indicates that the layer of Mg(2+) ions lowers the non-bonding B "pi" (p_z) bands relative to the bonding "sigma" (sp_xp_y) bands compared to graphite, causing sigma --> pi…

Superconductivity · Physics 2009-11-07 J. M. An , W. E. Pickett

We present the structural, electronic and superconducting properties of Li2B2 under pressure within the framework of the density functional theory. The structural parameters, electronic band structure, phonon frequency of the E2g phonon…

Superconductivity · Physics 2014-01-08 Edgar Martínez-Guerra , Filiberto Ortíz-Chi , Stefano Curtarolo , Romeo de Coss

Within the framework of non-stationary Ginzburg-Landau equations generalized on a case of two order parameters, we investigated dynamic characteristics of two-band superconducting MgB2 filaments in a voltage-driven regime. We calculated…

Superconductivity · Physics 2012-09-20 V. N. Fenchenko , Y. S. Yerin

Thermodynamic properties of the multiband superconductor MgB$_{2}$ have often been described using a simple sum of the standard BCS expressions corresponding to $\sigma$- and $\pi$-bands. Although, it is \textit{a priori} not clear if this…

Superconductivity · Physics 2009-11-11 Oleg V. Dolgov , Reinhard K. Kremer , Jens Kortus , Alexander A. Golubov , Sergei V. Shulga

We present the results of the first directional point-contact spectroscopy experiments in high-quality MgB_2 single crystals. Due to the directionality of the current injection into the samples, the application of a magnetic field allowed…

Superconductivity · Physics 2009-11-07 R. S. Gonnelli , D. Daghero , G. A. Ummarino , V. A. Stepanov , J. Jun , S. M. Kazakov , J. Karpinski

We review the current situation in the theory of superconducting and transport properties of MgB2. First principle calculations of of the electronic structure and electron-phonon coupling are discussed and compared with the experiment. We…

Superconductivity · Physics 2009-11-07 I. I. Mazin , V. P. Antropov

Through a comprehensive free energy analysis, we demonstrate that finite temperature can simultaneously weaken superconductivity and mitigate spin polarization induced depairing, leading to potential non-monotonic temperature-dependent…

Superconductivity · Physics 2025-11-25 Xusheng Wang , Lianyi He , Shuai-hua Ji

Using Scanning Tunneling Microscope at low temperature we explore the superconducting phase diagram in the $\pi$-band of the two-band superconductor MgB$_2$. In this band the peculiar shape of the local tunneling spectra and their dynamics…

Transport and thermodynamic properties of a sintered pellet of the newly discovered $MgB_2$ superconductor have been measured to determine the characteristic critical magnetic fields and critical current densities. Both resistive transition…

Superconductivity · Physics 2009-11-07 D. K. Finnemore , J. E. Ostenson , S. L. Bud'ko , G. Lapertot , P. C. Canfield

We study the electronic structure in the vicinity of a vortex in a two-band superconductor in which the quasiparticle motion is ballistic in one band and diffusive in the other. This study is based on a model appropriate for such a case,…

Superconductivity · Physics 2007-09-13 K. Tanaka , M. Eschrig , D. F. Agterberg

We study the Ginzburg-Landau model of superconductivity in three dimensions and for strong external magnetic fields. For magnetic field strengths above the phenomenologically defined second critical field it is known from Physics that…

Mathematical Physics · Physics 2011-10-20 S. Fournais , A. Kachmar , M. Persson

This review paper illustrates the main normal and superconducting state properties of magnesium diboride, a material known since early 1950's, but recently discovered to be superconductive at a remarkably high critical temperature Tc=40K…

Superconductivity · Physics 2007-05-23 Cristina Buzea , Tsutomu Yamashita