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The recent discovery of superconductivity up to 32 K in the pressurized MoB2 revives the interests in exploring novel superconductors in transition-metal diborides isostructural to MgB2. Although the Mo 4d-electrons participate in Cooper…

We have observed a strongly broadened Raman band of MgB2 that shows anomalously large pressure dependence of its frequency. This band and its pressure dependence can be interpreted as the E2g zone center phonon, which is strongly anharmonic…

Isotope effects in a multiband superconductor with a leading interband pairing channel are investigated. A relatively small electron-phonon contribution into the pair-transfer interaction can cause effects of observed magnitude. A multiband…

Superconductivity · Physics 2007-05-23 N. Kristoffel , P. Rubin

Room temperature Raman scattering measurements have been carried out on well characterized samples of MgB2-xCx. The Raman line corresponding to the E2g phonon mode shows progressive hardening from 620 cm-1 in pristine MgB2 to 775 cm-1 in…

Superconductivity · Physics 2009-11-11 T. Sakuntala , A. Bharathi , S. K. Deb , N. Gayathri , C. S. Sundar , Y. Hariharan

We have studied the lattice dynamics, electron-phonon coupling, and superconducting properties of $\alpha$-MoB$_2$, as a function of applied pressure, within the framework of density functional perturbation theory using a mixed-basis…

Superconductivity · Physics 2023-10-31 Marco-Antonio Carmona-Galván , Rolf Heid , Omar De la Peña-Seaman

This work builds upon the recent demonstration of a phononic four-wave mixing (FWM) pathway mediated by parametric resonance. In such a process, drive tones f_d1 and f_d2 associated with a specific phonon mode interact such that one of the…

Pattern Formation and Solitons · Physics 2017-10-16 Adarsh Ganesan , Cuong Do , Ashwin Seshia

The titular manuscript invites a description of the background of research on MgB$_2$,whose unique electron-phonon coupling strength and record superconducting T$_c$ for such a material at ambient pressure was demonstrated by the combined…

Superconductivity · Physics 2023-06-06 Warren E. Pickett

In this paper, we reexamine the results of isotope effect experiments of the conventional monoatomic superconductor (Hg). It is shown clearly that the isotopic coefficients of mercury can be largely deviated from $\alpha=0.5$, the standard…

Superconductivity · Physics 2011-02-09 X. Q. Huang

The phonon Boltzmann transport equation (BTE) is a powerful tool for studying non-diffusive thermal transport. Here, we develop a new universal variational approach to solving the BTE that enables extraction of phonon mean free path (MFP)…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 Vazrik Chiloyan , Lingping Zeng , Samuel Huberman , Alexei A. Maznev , Keith A. Nelson , Gang Chen

In previous theoretical studies of phonon-mediated superconductors, the electron-phonon coupling is treated by solving the Migdal-Eliashberg equations under the bare vertex approximation, whereas the effect of Coulomb repulsion is…

Superconductivity · Physics 2023-10-24 Jie Huang , Zhao-Kun Yang , Xiao-Yin Pan , Guo-Zhu Liu

We report the systematic investigation of the specific heat of the noncentrosymmetric supercon- ductor Li2(Pd1-xPtx)3B as a function of x. There is a large deviation of the phononic specific heat from the conventional Debye specific heat…

Superconductivity · Physics 2013-05-10 G. Eguchi , D. C. Peets , M. Kriener , S. Yonezawa , G. Bao , S. Harada , Y. Inada , G. -q. Zheng , Y. Maeno

The coupling between quasiparticles and bosonic excitations rules the energy transfer pathways in condensed matter systems. The possibility of inferring the strength of specific coupling channels from their characteristic time scales…

The superconducting order parameter and electron-phonon interaction (EPI) in a MgB$_{2}$ c-axis oriented thin film are investigated by point contacts (PCs). Two superconducting gaps $\Delta_{Small}\approx 2.6$ meV and $\Delta_{Large}\approx…

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

We present a combined density-functional-perturbation-theory and inelastic neutron scattering study of the lattice dynamical properties of YNi2B2C. In general, very good agreement was found between theory and experiment for both phonon…

Superconductivity · Physics 2015-06-19 F. Weber , L. Pintschovius , W. Reichardt , R. Heid , K. -P. Bohnen , A. Kreyssig , D. Reznik , K. Hradil

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

We study the impact of a time-dependent external driving of the lattice phonons in a minimal model of a BCS superconductor. Upon evaluating the driving-induced vertex corrections of the phonon-mediated electron-electron interaction, we show…

Superconductivity · Physics 2016-11-15 A. Komnik , M. Thorwart

We characterize the superconducting state of phase pure polycrystalline samples of the new layered superconductor MgB$_2$ by specific heat measurements in magnetic fields up to 9 T. The characteristic jump at the superconducting transition…

Superconductivity · Physics 2007-05-23 R. K. Kremer , B. J. Gibson , K. Ahn

Two-dimensional (2D) boron has been predicted to show superconductivity. However, intrinsic 2D carbon and phosphorus have not been reported to be superconductors, which, inspires us to seek superconductivity in their mixture. Here we…

Superconductivity · Physics 2018-05-23 Bao-Tian Wang , Peng-Fei Liu , Tao Bo , Wen Yin , Fangwei Wang

Heat capacity measurements on the recently discovered geometrically frustrated beta-pyrochlore superconductor RbOs2O6 (Tc=6.4 K) yield a Sommerfeld coefficient of 44 mJ/(molf.u. K^2). This is about 4 times larger than the one found in band…

Superconductivity · Physics 2009-11-11 M. Brühwiler , S. M. Kazakov , J. Karpinski , B. Batlogg