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Related papers: Two band superconductivity in MgB2: basic anisotro…

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The angular and temperature dependence of the upper critical field Hc2 in MgB2 was determined from torque magnetometry measurements on single crystals. The Hc2 anisotropy gamma_H was found to decrease with increasing temperature, in…

Superconductivity · Physics 2009-11-07 M. Angst , R. Puzniak , A. Wisniewski , J. Roos , H. Keller , P. Miranovic , J. Jun , S. M. Kazakov , J. Karpinski

Anisotropic properties of superconducting MgB2 obtained by torque magnetometry are compared to theoretical predictions, concentrating on two issues. Firstly, the angular dependence of Hc2 is shown to deviate close to Tc from the dependence…

Superconductivity · Physics 2009-11-10 M. Angst , D. Di Castro , R. Puzniak , A. Wisniewski , J. Jun , S. M. Kazakov , J. Karpinski , S. Kohout , H. Keller

Two-band superconductivity has become an important topic over the last ten years. Extensive experimental and theoretical studies started with MgB2 and are now focused on the iron-based and other new superconductors. In this review, I…

Superconductivity · Physics 2014-02-18 M. Zehetmayer

The recently discovered superconductivity in MgB2 has captured world attention due to its simple crystal structure and relatively high superconducting transition temperature Tc=39K. It appears to be generally accepted that it is…

Superconductivity · Physics 2009-11-07 A. I. Posazhennikova , T. Dahm , K. Maki

We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB$_{2}$. Experiments are proposed which lead to identification of the possible scenarios: whether both $\sigma $- and $\pi $-bands superconduct or $\sigma…

Superconductivity · Physics 2007-05-23 V. A. Ivanov , J. J. Betouras , F. M. Peeters

The recently discovered superconductivity in MgB2 has created the world sensation. In spite of the relatively high superconducting transition temperature Tc=39K, the superconductivity is understood in terms of rare two gap superconductor…

Superconductivity · Physics 2007-05-23 T. Dahm , A. I. Posazhennikova , K. Maki

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

The microscopic superconductivity theory in MgB2 systems in the magnetic fields directed parallel and perpendicular to the plane (ab) is built. The two energy bands of different dimensions overlapping on the Fermi surface (two-dimensional…

Superconductivity · Physics 2008-11-07 M. E. Palistrant , I. D. Cebotari , V. A. Ursu

The anisotropy gamma of the superconducting state of high quality single-crystals of MgB2 was determined, using torque magnetometry with two different methods. The anisotropy of the upper critical field was found to be temperature…

Superconductivity · Physics 2008-11-28 M. Angst , R. Puzniak , A. Wisniewski , J. Jun , S. M. Kazakov , J. Karpinski , J. Roos , H. Keller

The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta1=2.3 meV and Delta2=7.1 meV. Different spectral weights of the partial…

Superconductivity · Physics 2009-11-07 M. Iavarone , G. Karapetrov , A. E. Koshelev , W. K. Kwok , G. W. Crabtree , D. G. Hinks

It is well established that the superconductivity in the recently discovered superconducting compound MgB$_{2}$ resides in the quasi-two-dimensional band ($\sigma$-band) and three-dimensional band ($\pi$-band). We demonstrate that, due to…

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

It has recently been observed that MgB_2 is a superconductor with a high transition temperature. Here we propose a model of anisotropic s-wave superconductivity which consistently describes the observed properties of this compound,…

Superconductivity · Physics 2009-11-07 Stephan Haas , Kazumi Maki

In-plane electrical transport properties of MgB2 single crystals grown under high pressure of 4-6 GPa and temperature of 1400-1700oC in Mg-B-N system have been measured. For all specimens we found sharp superconducting transition around…

Superconductivity · Physics 2009-11-07 Yu. Eltsev , S. Lee , K. Nakao , N. Chikumoto , S. Tajima , N. Koshizuka , M. Murakami

We report on study of the electronic anisotropy of the newly discovered MgB2 superconductor using the in-plane resistivity measurements in magnetic field applied perpendicular and parallel to Mg and B planes of MgB2 single crystals. The…

Superconductivity · Physics 2009-11-07 Yu. Eltsev , S. Lee , K. Nakao , N. Chikumoto , S. Tajima , N. Koshizuka , M. Murakami

Based on the experimentally found existence of two gaps in MgB2 (one gap associated to the boron sigma-states and the other to the boron pi-states), the different contributions to the transport properties, electrical conductivity and Hall…

Superconductivity · Physics 2007-05-23 Pablo de la Mora , Miguel Castro , Gustavo Tavizon

We report on measurements and a detailed analysis of the reversible magnetization of superconducting NbSe2 single crystals. By comparing the experimental data with Ginzburg Landau theory we show that superconductivity in NbSe2 cannot be…

Superconductivity · Physics 2010-07-21 M. Zehetmayer , H. W. Weber

We show that a two-band model with ${\bf k}$-dependent superconducting gaps well describes the transmission and optical conductivity measured for MgB$_2$ thin films. It is also shown that the two-band anisotropic model consistently…

Superconductivity · Physics 2009-11-10 Takashi Yanagisawa , Hajime Shibata

Despite the intense activity in the year since the discovery of superconductivity in MgB2, key parameters, in particular the upper and lower critical fields Hc2 and Hc1 and their anisotropies, are not well-established, largely because of…

Superconductivity · Physics 2009-11-07 G. K. Perkins , J. Moore , Y. Bugoslavsky , L. F. Cohen , J. Jun , S. M. Kazakov , J. Karpinski , A. D. Caplin

The superconducting phase diagram of MgB2 was determined from magnetization, magneto-transport and the first single-crystal specific heat measurements. A zero-temperature in-plane coherence length of 8 nm is determined. The superconducting…

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
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