Efficient 
<i>ab initio</i>
 Migdal-Eliashberg calculation considering the retardation effect in phonon-mediated superconductors

Wang, Tianchun; Nomoto, Takuya; Nomura, Yusuke; Shinaoka, Hiroshi; Otsuki, Junya; Koretsune, Takashi; Arita, Ryotaro

doi:10.1103/physrevb.102.134503

Cited by 24 publications

References 40 publications

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“…were developed to further improve numerical efficiency. [162][163][164] The method provides momentum-and frequency-dependent self-energies in the regime of weak to intermediate coupling strength and was successfully applied to multi-band high-Tc superconductors. [104,153,154] As for future work it might be interesting to extend multiorbital TPSC to study further neighbor interactions as was already done for the single-orbital TPSC [146][147][148] or superconductivity as was already started in ref.…”

Section: Discussionmentioning

confidence: 99%

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Two‐Particle Self‐Consistent Method for the Multi‐Orbital Hubbard Model

2021

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One of the most challenging problems in solid state systems is the microscopic analysis of electronic correlations. A paramount minimal model that encodes correlation effects is the Hubbard Hamiltonian, which—regardless of its simplicity—is exactly solvable only in a few limiting cases and approximate many‐body methods are required for its solution. In this review, an overview on the non‐perturbative two‐particle self‐consistent method (TPSC), which was originally introduced to describe the electronic properties of the single‐band Hubbard model, is presented. A detailed derivation of the multi‐orbital generalization of TPSC is introduced here and particular features of the method on exemplary interacting models in comparison to dynamical mean‐field theory results are discussed.

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Section: Discussionmentioning

confidence: 99%

“…In addition, new numerical techniques were developed to further improve numerical efficiency. [ 162–164 ] The method provides momentum‐ and frequency‐dependent self‐energies in the regime of weak to intermediate coupling strength and was successfully applied to multi‐band high‐Tc superconductors. [ 104,153,154 ]…”

Section: Discussionmentioning

confidence: 99%

Two‐Particle Self‐Consistent Method for the Multi‐Orbital Hubbard Model

2021

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“…In addition, recently, computational techniques using the compact IR basis have been developed to calculate the dynamic susceptibility [32][33][34]. It is expected that by using the basis obtained by SpM-Padé, the accuracy of these analytic calculations will be improved.…”

Section: Discussionmentioning

confidence: 99%

Robust analytic continuation combining the advantages of the sparse modeling approach and Padé approximation

Motoyama,

Yoshimi,

Otsuki

2021

Preprint

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Analytic continuation (AC) from the imaginary-time Green's function to the spectral function is a crucial process for numerical studies of the dynamical properties of quantum many-body systems. This process, however, is an ill-posed problem; that is, the obtained spectrum is unstable against the noise of the Green's function. Though several numerical methods have been developed, each of them has its own advantages and disadvantages. The sparse modeling (SpM) AC method, for example, is robust against the noise of the Green's function but suffers from unphysical oscillations in the lowenergy region. We propose a new method that combines the SpM AC with the Padé approximation. This combination, called SpM-Padé, inherits robustness against noise from SpM and low-energy accuracy from Padé, compensating for the disadvantages of each. We demonstrate that the SpM-Padé method yields low-variance and low-biased results with almost the same computational cost as that of the SpM method.

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“…The above value is in general agreement with the screened Coulomb interaction (0.24) calculated recently for LaH 10 using the efficient ab initio Migdal–Eliashberg method considering the retardation effects. [ 52 ] The Heaviside step function θ is determined by a cutoff frequency, whose value is set to ten times the maximum phonon frequency. The value of β is given by

β = 1 / k_{normalB} T

, where

k_{B}

is the Boltzmann constant.…”

Section: Theoretical Model and Computational Methodsmentioning

confidence: 99%

Evidence of Phonon‐Mediated Superconductivity in LaH ₁₀ at High Pressure

Durajski

Wang

et al. 2020

ANNALEN DER PHYSIK

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Motivated by the recent experimental discovery of the high‐critical‐temperature superconductor LaH10 (250–260 K at high pressures 170–190 GPa), the influence of H isotope substitution on the phonon spectra, electron–phonon interactions, and thermodynamic properties of superconducting LaH10−xDx (x=0,2,5,8,10) at 250 GPa are studied. On the basis of first‐principles calculations, it is found that all investigated systems are dynamically stable in a clathrate structure with space group Fm3¯m and exhibit high superconducting critical temperatures Tc ranging from 169 to 234 K. The dominant role of hydrogen in enhancing Tc is examined by numerically solving the Eliashberg equations. The estimated critical temperature, superconducting energy gap, specific heat, and thermodynamic critical field demonstrate that the underlying mechanism of superconductivity in lanthanum hydride is conventional electron–phonon coupling, which manifests itself in terms of isotope effect.

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Efficient ab initio Migdal-Eliashberg calculation considering the retardation effect in phonon-mediated superconductors

Cited by 24 publications

References 40 publications

Two‐Particle Self‐Consistent Method for the Multi‐Orbital Hubbard Model

Two‐Particle Self‐Consistent Method for the Multi‐Orbital Hubbard Model

Robust analytic continuation combining the advantages of the sparse modeling approach and Padé approximation

Evidence of Phonon‐Mediated Superconductivity in LaH ₁₀ at High Pressure

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Efficient ab initio Migdal-Eliashberg calculation considering the retardation effect in phonon-mediated superconductors

Cited by 24 publications

References 40 publications

Two‐Particle Self‐Consistent Method for the Multi‐Orbital Hubbard Model

Two‐Particle Self‐Consistent Method for the Multi‐Orbital Hubbard Model

Robust analytic continuation combining the advantages of the sparse modeling approach and Padé approximation

Evidence of Phonon‐Mediated Superconductivity in LaH 10 at High Pressure

Contact Info

Product

Resources

About

Evidence of Phonon‐Mediated Superconductivity in LaH ₁₀ at High Pressure