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Related papers: Multiband model for penetration depth in MgB2

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Theoretical calculations of materials have in recent years shown promise in facilitating the analysis of convoluted experimental data. This is particularly invaluable in complex systems or for materials subject to certain environmental…

The conductance of systems containing two tunnel point-contacts and a single subsurface scatterer is investigated theoretically. The problem is solved in the approximation of s-wave scattering giving analytical expressions for the wave…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 N. V. Khotkevych , Yu. A. Kolesnichenko , J. M. van Ruitenbeek

The two gaps in a two-band clean s-wave superconductor are evaluated self-consistently within the quasiclassical Eilenberger weak-coupling formalism with two in-band and one inter-band pairing potentials. Superfluid density, free energy and…

Superconductivity · Physics 2009-10-28 V. G. Kogan , C. Martin , R. Prozorov

The effective superconducting penetration depth measured in the vortex state of PrOs4Sb12 using transverse-field muon spin rotation (TF-muSR) exhibits an activated temperature dependence at low temperatures, consistent with a nonzero gap…

The upper critical field in MgB2 is investigated in the framework of the two-gap Ginzburg-Landau theory. A variational solution of linearized Ginzburg-Landau equations agrees well with the Landau level expansion and demonstrates that…

Superconductivity · Physics 2009-11-11 V. H. Dao , M. E. Zhitomirsky

We use density functional theory to calculate the electronic band structures, cohesive energies, phonon dispersions, and optical absorption spectra of two-dimensional In$_2$X$_2$ crystals, where X is S, Se, or Te. We identify two…

Mesoscale and Nanoscale Physics · Physics 2014-09-19 V. Zolyomi , N. D. Drummond , V. I. Fal'ko

We report data on the thermal conductivity K(T,H) along the basal plane of the hexagonal crystal structure of superconducting Mg{1-y}Al{y}B2 with y=0.02 and 0.07 at temperatures between 0.5 and 50 K and in external magnetic fields between 0…

Superconductivity · Physics 2007-05-23 A. V. Sologubenko , N. D. Zhigadlo , J. Karpinski , H. R. Ott

The pointlike impurity scattering is studied for a superconductor with different pairing symmetries based on a minimal two band model proposed by S. Raghu $et$ $al.$ [Phys. Rev. B {\bf 77}, R220503 (2008)], and the self-consistent…

Superconductivity · Physics 2009-11-10 Tao Zhou , Xiang Hu , Jian-Xin Zhu , C. S. Ting

The anisotropy of MgB2 is still under debate: its value, strongly dependent on the sample and on the measuring method, ranges between 1.2 and 13. In this work we present our results on a MgB2 c-oriented superconducting thin film. To…

Superconductivity · Physics 2009-11-07 C. Ferdeghini , V. Braccini , M. R. Cimberle , D. Marre , P. Manfrinetti , V. Ferrando , M. Putti , A. Palenzona

The electron-phonon interaction in magnesium diboride MgB_2 single crystals is investigated by point-contact (PC) spectroscopy. For the first time the electron coupling with E_2g phonon modes is resolved in the PC spectra. The correlation…

Superconductivity · Physics 2009-11-07 Yu. G. Naidyuk , I. K. Yanson , O. E. Kvitnitskaya S. Lee , S. Tajima

A semi-empirical formalism based on the second moment tight binding approach, considering two bands is presented for deriving interatomic potentials for magnetic d-band materials and transition metal alloys. It incorporates an empirical…

Materials Science · Physics 2009-11-11 Graeme J. Ackland

We analyze superonductivity in MgB$_2$ observed below $T_c=39$ K resulting from electron-phonon coupling involving a mode at $\hbar \omega_1 = 24$ meV and most importantly the in-plane B-B $E_{2g}$ vibration at $\hbar \omega_2=67$ meV. The…

Superconductivity · Physics 2009-11-07 C. Joas , I. Eremin , D. Manske , K. H. Bennemann

Transition metal dichalcogenides (TMDs) are promising candidates for a wide variety of ultrascaled electronic, quantum computation, and optoelectronic applications. The exponential decay of electronic density of states into the bandgap,…

Mesoscale and Nanoscale Physics · Physics 2023-08-04 Prasad Sarangapani , James Charles , Tillmann Kubis

Complex electronic band structures, with multiple valleys or bands at the same or similar energies can be beneficial for thermoelectric performance, but the advantages can be offset by inter-valley and inter-band scattering. In this paper,…

Materials Science · Physics 2017-11-22 Evan Witkoske , Xufeng Wang , Vahid Askarpour , Mark Lundstrom , Jesse Maassen

A model for description of materials with narrow energy bands is proposed. It is shown that in narrow-band materials electron-hole symmetry is absent in contrast to the Hubbard model. In this paper metal-insulator transition is studied. The…

Strongly Correlated Electrons · Physics 2007-05-23 Leonid Didukh

To understand the superconductivity in MgB2, several two-band models of superconductivity were proposed. In this paper, by using the relativistic fermion model, we clearize the effect of the lower band in the superconductivity.

Superconductivity · Physics 2007-05-23 Tadafumi Ohsaku

We study the effects of anisotropic order parameters on the temperature dependence of London penetration depth anisotropy $\gamma_\lambda(T)$. After MgB$_2$, this dependence is commonly attributed to distinct gaps on multi-band Fermi…

Superconductivity · Physics 2022-01-10 V. G. Kogan , R. Prozorov

We study the new binary intermetallic superconductor MgB2 using high-resolution photo-emission spectroscopy. The superconducting-state spectrum measured at 5.4 K shows a coherent peak with a shoulder structure, in sharp contrast to that…

Superconductivity · Physics 2009-11-07 S. Tsuda , T. Yokoya , T. Kiss , Y. Takano , K. Togano , H. Kitou , H. Ihara , S. Shin

One of the features of the unconventional $s_\pm$ state in iron-based superconductors is possibility to transform to the $s_{++}$ state with the increase of the nonmagnetic disorder. Detection of such a transition would prove the existence…

Superconductivity · Physics 2021-06-07 V. A. Shestakov , M. M. Korshunov , Yu. N. Togushova , O. V. Dolgov

We present the results of a spectroscopic study of state-of-the-art MgB2 single crystals, carried out by using a modified point-contact technique. The use of single crystals allowed us to obtain point contacts with current injection either…

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