English
Related papers

Related papers: Multiband model for penetration depth in MgB2

200 papers

We consider the far-infrared and the microwave conductivities of a two-band superconductor with non-magnetic impurities. The strong coupling expressions for the frequency and temperature dependent conductivity of a two-band superconductor…

Superconductivity · Physics 2015-05-13 Bozidar Mitrovic

The two tone intermodulation distortion arising in MgB2 thin films synthesized by hybrid physical-chemical vapour deposition is studied in order to probe the influence of the two bands on the nonlinear response of this superconductor. The…

Superconductivity · Physics 2009-11-11 G. Cifariello , M. Aurino , E. Di Gennaro , G. Lamura , A. Andreone , P. Orgiani , X. X. Xi , J. -C. Villegier

The penetration depth lambda of MgB2 was deduced from both the ac susceptibility chi and the magnetization M(H) of sorted powders. The good agreement between the two sets of data without geometric correction for the grain orientation…

Superconductivity · Physics 2009-11-07 X. H. Chen , Y. Y. Xue , R. L. Meng , C. W. Chu

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 present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB_2 and the isostructural AlB_2 within the framework of density functional perturbation theory using a mixed-basis…

Superconductivity · Physics 2009-11-07 K. -P. Bohnen , R. Heid , B. Renker

The temperature dependence of the London penetration depth, $\lambda(T)$, was measured in polycrystalline MgB$_2$ samples by a high-resolution, radio frequency technique. A clear exponential temperature dependence of $\lambda(T)$ was…

Superconductivity · Physics 2007-05-23 F. Manzano , A. Carrington

We report first-principles calculations of the electronic band structure and lattice dynamics for the new superconductor MgB$_{2}$. The excellent agreement between theory and our inelastic neutron scattering measurements of the phonon…

We apply the generalized two-band model of superconductivity to calculate the electronic contribution to the specific heat, superconducting gaps and electron-boson coupling constants of the multi-band layered superconductors MgB2 and…

Superconductivity · Physics 2011-07-26 E. G. Maksimov , A. E. Karakozov , B. P. Gorshunov , E. S. Zhukova , Ya. G. Ponomarev , M. Dressel

We report magnetoresistance (MR) measurements on MgB2 and the corresponding full account from ab-initio calculations; we suggest that this combination can be a useful tool to probe electron- phonon coupling. We obtain good quantitative…

A simple two-band model with interband scattering of intraband pairs is applied to MgB$_2$ superconductivity. An adjustable parameters set is chosen. The calculated $T_c$ vs doping, isotope exponent and the heat capacity jump are in…

Superconductivity · Physics 2016-08-31 N. Kristoffel , T. Örd

The theory of thermodynamic properties of two-band superconductor with reduced density charge carriers is developed on the base of phonon superconducting mechanism with strong electron-phonon interaction. This theory is adapted to describe…

Superconductivity · Physics 2015-06-25 M. E. Palistrant , V. A. Ursu

The magnetic penetration depth, $\lambda^{-2}(T)$, in the basal plane of a magnesium diboride (MgB$_2$) film was measured using a two-coil mutual inductance technique at 50 kHz. This film has $T_c\simeq 38$ K, $\Delta T_c \leq 1$ K, and…

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

Magnesium diboride MgB2 has been an extraordinarily hot research topic since the discovery of superconductivity below 40 K, due to the vast amount of unusual properties originating from the involvement in superconductivity of two sets of…

Superconductivity · Physics 2007-05-23 M. Angst , R. Puzniak

Taking as a starting point the results of LDA calculations, which show that in MgB2 the phonons have a strong quartic anharmonicity and that the bond-stretching electron-phonon interaction (EPI) has both a linear and a large quadratic…

Superconductivity · Physics 2009-11-10 M. Acquarone , L. Romano'

In order to understand the unexpected superconducting behavior of MgB$_2$ compound we have made electronic structure calculations for MgB$_2$ and closely related systems. Our calculated Debye temperature from the elastic properties indicate…

Superconductivity · Physics 2009-11-07 P. Ravindran , P. Vajeeston , R. Vidya , A. Kjekshus , H. Fjellvåg

I calculated the effect of magnetic impurities on the normal and superconductive properties of a multiband s-wave superconductor by direct solution of the two-band Eliashberg equations. In this way I determined the critical temperature, the…

Superconductivity · Physics 2007-05-23 G. A. Ummarino

The impurity concentration dependence of superconducting transition temperature $T_c$ is studied within the framework of two band model of order parameter anisotropy. Both intraband and interband electron scattering by nonmagnetic and…

Superconductivity · Physics 2007-05-23 P. I. Arseev , N. K. Fedorov , S. O. Loiko

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 report the results of an ab initio modeling of substitutional impurities such as zinc, copper and zirconium ions incorporated into the magnesium sublattice of MgB2. The goal of computational studies was to gain an atomistic understanding…

Materials Science · Physics 2011-10-21 Aleksandr Pishtshev , Mihhail Klopov