Related papers: Migdal-Eliashberg equations - the effective model …
We calculate superconducting transition temperatures ($T_{\rm c}$) in sulfur hydrides H$_{2}$S and H$_{3}$S from first principles using the density functional theory for superconductors. At pressures of $\lesssim$150 GPa, the high values of…
We discuss the compatibility of the most accurate experimental data with the ordinary Migdal-Eliashberg theory of superconductivity in the fullerene compound Rb_3C_60. By using different model phonon spectra we conclude that the…
In this paper, we calculate the superconducting critical temperature as a function of pressure, Tc(P ), using a method based on the functional derivative of the critical temperature with the Eliashberg function, dTc/dA2F. The coulomb…
Based on BCS model with the external pair potential formulated in a work Grigorishin (2017) [1], analogous model with electron-phonon coupling and Coulomb coupling is proposed. The generalized Eliashberg equations in the regime of…
Motivated by the recent experimental progress in studying conventional and unconventional superconductors in a pump-probe setup, we perform a comprehensive theoretical analysis of the nonlinear response of a diffusive BCS conventional…
We address an issue of how to accurately include the self energy effect of the screened electron-electron Coulomb interaction in the phonon-mediated superconductors from first principles. In the Eliashberg theory for superconductors, self…
Experimental discovery that compressed sulphur hydride exhibits superconducting transition temperature Tc=203 K (Drozdov et al 2015 Nature 525 73) sparked intensive studies of superconducting hydrides. However, this discovery was not a…
The magnitude and the temperature dependence of the superconducting order parameter {\Delta}(T) of single-crystals of Cd2Re2O7 (Tc = 1.02 K) was measured using point contact spectroscopy. In order to fit the conductance spectra and to…
In this study, we explore lithium-doped stable molecular hydrogen structures by performing first-principles crystal structure searches across varying compositions in the Li-H system under high pressure. Our search reveals a cubic phase of…
The implementation of electron- and hole-doping, in conjunction to applied pressure, is analyzed as a mechanism to induce or enhance the superconducting state on fcc YH$_3$ and ScH$_3$. In particular, the evolution of their structural,…
The properties of the superconducting and the anomalous normal state have been described by using the Eliashberg method. The pairing mechanism has been reproduced with help of the Hamiltonian, which models the electron-phonon and…
Polycrystalline sample of superconducting ThIr$_{3}$ was obtained by arc-melting Th and Ir metals. Powder x-ray diffraction revealed that the compound crystalizes in a rhombohedral crystal structure (R-3m, s.g. no. 166) with the lattice…
We present ab-initio calculations of the quasi-harmonic temperature dependent elastic constants. The isothermal elastic constants are calculated at each temperature as second derivatives of the Helmholtz free energy with respect to strain…
Making use of generalized Eliashberg equations, we describe the Altshuler-Aronov (AA) effect and superconductivity on equal footing. We derive explicit expressions for the Coulomb pseudopotential in 3D, taking into account also the…
We present an ab initio analysis with density functional theory for superconductors (SCDFT) to understand the superconducting mechanism of doped layered nitrides \beta-Li$_x$MNCl (M=Ti, Zr, and Hf). The current version of SCDFT is based on…
Using muon-spin rotation the pressure-induced superconductivity in the Bi-III phase of elemental Bismuth (transition temperature $T_{\rm c}\simeq7.05$ K) was investigated. The Ginzburg-Landau parameter $\kappa=\lambda/\xi=30(6)$ ($\lambda$…
We formulate an efficient scheme to perform Migdal-Eliashberg calculation considering the retardation effect from first principles. While the conventional approach requires a huge number of Matsubara frequencies, we show that the…
We show that the Migdal-Eliashberg theory loses validity at a finite value $\lambda_c$ of the electron-phonon coupling $\lambda$ regardless of the underlying model Hamiltonian. The value of $\lambda_c$ is approximately between 3.0 and 3.7.…
The ab initio calculations suggest (Y. Ma et al.), that the high-pressure ($p=200$~GPa) superconducting state in $\rm{BiH_{5}}$ and $\rm{BiH_{6}}$ compounds characterizes with a high value of the critical temperature ($T_{C}\sim 100$~K).…
A strong-coupling expansion is applied to the anharmonic Holstein model and to the Holstein-Hubbard model through fourth order in the hopping matrix element. Mean-field theory is then employed to determine transition temperatures of the…