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Related papers: Interband scattering in MgB2

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We studied the far-infrared reflectance of superconducting MgB2 in and out of equilibrium using pulsed synchrotron radiation. The equilibrium data can be described by a single energy gap at 2 Delta / hc = 43 cm-1. The fit improves slightly…

Superconductivity · Physics 2007-05-23 R. P. S. M. Lobo , J. J. Tu , Eun-Mi Choi , Hyeong-Jin Kim , W. N. Kang , Sung-Ik Lee , G. L. Carr

We report the boron isotope effect on the E2g phonon mode by micro-Raman spectroscopy on the ternary Mg1-xAlxB2 system, synthesized with pure isotopes 10B and 11B. The isotope coefficient on the phonon frequency is near 0.5 in the full…

Superconductivity · Physics 2013-04-09 L. Simonelli , V. Palmisano , M. Fratini , M. Filippi , P. Parisiades , D. Lampakis , E. Liarokapis , A Bianconi

We present a Raman scattering study of the E2g phonon anharmonicity and of superconductivity induced self-energy effects in MgB2 single crystals. We show that anharmonic two phonon decay is mainly responsible for the unusually large…

Superconductivity · Physics 2009-11-13 A. Mialitsin , B. S. Dennis , N. D. Zhigadlo , J. Karpinski , G. Blumberg

Using the tight-binding method for the $\pi$-bands in MgB$_2$, the Hubbard on-site Coulomb interaction on two inequivalent boron $p_z$-orbitals is transformed into expressions in terms of $\pi$-band operators. For scattering processes…

Superconductivity · Physics 2009-11-07 Kunihiko Yamaji

We report tunneling measurements of the electron-phonon (e-ph) interaction in superconducting MgB$_2$ using the MgB$_2$-I-Nb junctions, where I stands for insulator. The phonon structure in tunneling density of states in MgB$_2$ clearly…

Superconductivity · Physics 2007-05-23 A. I. D'yachenko , V. Yu. Tarenkov , A. V. Abal'oshev , S. J. Lewandowski

We compute the anharmonic shift of the phonon frequencies in MgB2, using density functional theory. We explicitly take into account the scattering between different phonon modes at different q-points in the Brillouin zone. The shift of the…

Superconductivity · Physics 2009-11-10 Michele Lazzeri , Matteo Calandra , Francesco Mauri

Phonon spectra have been investigated by micro-Raman scattering from 290 to 20K. New peaks at 500 and 674 cm-1 appear below 250K in MgB2. These peaks are explained by the Fermi resonance, where Raman-active E2g intereacts with the overtone…

Superconductivity · Physics 2007-05-23 N. Ogita , T. Kariya , K. Hiraoka , J. Nagamatsu , T. Muranaka , H. Takagiwa , J. Akimitsu , M. Udagawa

It is shown that the sharp peak in the $E_{2g}$ Raman spectrum of superconducting $MgB_2$ is due to a bound state caused by the electron-phonon coupling. Our theory explains why this peak appears only in the spectra with $E_{2g}$ symmetry…

Superconductivity · Physics 2009-11-10 R. Zeyher

The phonon density-of-states of transition metal diborides TMB2 with TM = Ti, V, Ta, Nb and Y has been measured using the technique of inelastic neutron scattering. The experimental data are compared with ab initio density functional…

Superconductivity · Physics 2009-11-10 R. Heid , B. Renker , H. Schober , P. Adelmann , D. Ernst , K. -P. Bohnen

The transport in double-barrier heterostructures of electrons interacting with longitudinal optical phonons in the presence of parallel electric and magnetic fields is analyzed theoretically with the aid of a 3-dimensional quantum transport…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Dae Kwan Kim , Patrick Roblin , Kwang-Sup Soh , Chul Koo Kim

The paper presents detailed Raman scattering study of the unusually broad E2g phonon mode in MgB2 crystal. For the first time, it is shown by the polarized Raman scattering on few-micron-size crystallites with natural faces that the…

Superconductivity · Physics 2012-12-18 J. Hlinka , I. Gregora , J. Pokorny , A. Plecenik , P. Kus , L. Satrapinsky , S. Benacka

The electron-phonon interaction and related transport properties are investigated in monolayer silicene and MoS2 by using a density functional theory calculation combined with a full-band Monte Carlo analysis. In the case of silicene, the…

Mesoscale and Nanoscale Physics · Physics 2015-06-12 Xiaodong Li , Jeffrey T. Mullen , Zhenghe Jin , Kostyantyn M. Borysenko , M. Buongiorno Nardelli , Ki Wook Kim

Recent experimental evidence points to low-energy magnons as the primary contributors to the spin Seebeck effect. This spectral dependence is puzzling since it is not observed on other thermocurrents in the same material. Here, we argue…

Mesoscale and Nanoscale Physics · Physics 2016-05-16 I. Diniz , A. T. Costa

It is shown that the superconducting intermetallic compound MgB2 possesses a narrow, partly filled "superconducting band" with Wannier functions of special symmetry in its band structure. This result corroborates previous observations about…

Superconductivity · Physics 2011-03-03 Ekkehard Krüger

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

We present a comparison of electron-phonon interaction in NbB_2 and MgB_2, calculated using full-potential, density-functional-based methods in P6/mmm crystal structure. Our results, described in terms of (i) electronic structure, (ii)…

Superconductivity · Physics 2009-11-07 Prabhakar P. Singh

A short review of the optical and far-infrared measurements on MgB$_{2}$ is given. Multiband and multigap effects are analyzed by comparing optical properties with other experiments and {\em ab initio} calculations. The covered topics are:…

Superconductivity · Physics 2009-11-13 A. B. Kuzmenko

We present a microscopic quantum theory of intersubband polarons, quasiparticles originated from the coupling between intersubband transitions and longitudinal optical phonons. To this aim we develop a second quantized theory taking into…

Materials Science · Physics 2015-06-03 Simone De Liberato , Cristiano Ciuti

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

Chemical bonding and electronic structure of MgB2, a boron-based newly discovered superconductor, is studied using self-consistent band structure techniques. Analysis of the transformation of the band structure for the hypothetical series…

Condensed Matter · Physics 2009-11-07 K. D. Belashchenko , M. van Schilfgaarde , V. P. Antropov