Limits of Eliashberg theory and bounds for superconducting transition temperature

M.V. Sadovskii^†
Institute of Electrophysics, Ural Branch of the Russian Academy of Sciences, ul. Amundsena 106, Ekaterinburg, 620016, Russian Federation

The discovery of record-breaking values of superconducting transition temperature T_c in quite a number of hydrides under high pressure was an impressive demonstration of the capabilities of the electron—phonon mechanism of Cooper pairing. This led to increased interest in the foundations and limitations of the Eliashberg—McMillan theory as the main theory describing superconductivity in a system of electrons and phonons. Below, we shall consider both the elementary basics of this theory and a number of new results derived only recently. We shall discuss limitations on the value of the coupling constant related to lattice instability and a phase transition to another phase (CDW, bipolarons). Within the stable metallic phase, the effective pairing constant may acquire arbitrary values. We consider extensions beyond the traditional adiabatic approximation. It is shown that the Eliashberg—McMillan theory is also applicable in the strong antiadiabatic limit. The limit of very strong coupling, being the most relevant one for the physics of hydrides, is analyzed in detail. We also discuss the bounds for T_c appearing in this limit.

Keywords: Eliashberg equations, superconducting transition temperature, strong coupling, adiabatic and antiadiabatic approximation, superhydrides
PACS: 71.10.Fd, 74.20.−z, 74.20.Mn (all)
DOI: 10.3367/UFNe.2021.05.039007
URL: https://ufn.ru/en/articles/2022/7/f/
Web of Science

001100230300005
Scopus

2-s2.0-85182904304
ADS NASA

2022PhyU...65..724S
Citation: Sadovskii M V "Limits of Eliashberg theory and bounds for superconducting transition temperature" Phys. Usp. 65 724–739 (2022)

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Received: 12th, May 2021, accepted: 12th, May 2021

Оригинал: Садовский М В «Границы применимости теории Элиашберга и ограничения на температуру сверхпроводящего перехода» УФН 192 773–789 (2022); DOI: 10.3367/UFNr.2021.05.039007

References (55) Cited by (4) Similar articles (20) ↓

I.A. Troyan, D.V. Semenok et al “High-temperature superconductivity in hydrides” Phys. Usp. 65 748–761 (2022)
G.E. Volovik “Exotic Lifshitz transitions in topological materials” Phys. Usp. 61 89–98 (2018)
E.G. Maksimov, I. Božović et al “Scientific session of the Physical Sciences Division of the Russian Academy of Sciences “Room temperature superconductivity” (4&nbspOctober 2007)” Phys. Usp. 51 167–170 (2008)
E.G. Maksimov “Room-temperature superconductivity: myth or reality?” Phys. Usp. 51 167–170 (2008)
Yu.V. Kopaev, V.I. Belyavskii, V.V. Kapaev “With cuprate luggage to room-temperature superconductivity” Phys. Usp. 51 191–198 (2008)
V.I. Belyavskii, Yu.V. Kopaev “Ginzburg-Landau equations for high-temperature superconductors” Phys. Usp. 50 540–545 (2007)
A.D. Zaikin, D.S. Golubev et al “Quantum fluctuations and dissipation in thin superconducting wires” Phys. Usp. 41 226–230 (1998)
A. Gold “Superconductor-insulator transition in the disordered Bose condensate: a discussion of the mode-coupling approach” Phys. Usp. 41 217–220 (1998)
V.M. Pudalov “The metal-insulator transition in a two-dimensional system at zero magnetic field” Phys. Usp. 41 211–214 (1998)
V.L. Ginzburg “Phase transitions in ferroelectrics: some historical remarks” Phys. Usp. 44 1037–1043 (2001)
R. Chentsov “Fifth all-union conference on low-temperature physics” Sov. Phys. Usp. 2 329–336 (1959)
I.M. Eremin “Antiferromagnetism in iron-based superconductors: magnetic order in the model of delocalized electrons” Phys. Usp. 57 807–813 (2014)
V.N. Ryzhov, A.F. Barabanov et al “Theoretical studies of condensed matter” Phys. Usp. 51 1077–1083 (2008)
S.M. Stishov, L.G. Khvostantsev et al “On the 50th anniversary of the L F Vereshchagin Institute for High Pressure Physics, RAS (Scientific outreach session of the Physical Sciences Division of the Russian Academy of Sciences, 23 April 2008)” Phys. Usp. 51 1055–1083 (2008)
V.L. Ginzburg “A few comments on superconductivity research” Phys. Usp. 48 173–176 (2005)
V.I. Belyavskii, Yu.V. Kopaev “First International Conference ’Fundamental Problems of High-Temperature Superconductivity’” Phys. Usp. 48 177–182 (2005)
V.I. Belyavskii, Yu.V. Kopaev “Generalizing considerations about the nature of high-temperature superconductivity (based on the proceedings of M2S-HTSC-VII)” Phys. Usp. 47 409–416 (2004)
E.G. Maksimov “High-temperature superconductivity today” Phys. Usp. 47 957–958 (2004)
Yu.V. Kopaev “High-temperature superconductivity models” Phys. Usp. 45 655–659 (2002)
V.F. Gantmakher “Superconductor-insulator transitions and insulators with localized pairs” Phys. Usp. 41 214–217 (1998)

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