Analytic method for quadratic polarons in nonparabolic bands

S. N. Klimin, J. Tempere, M. Houtput, S. Ragni, T. Hahn, C. Franchini, A. S. Mishchenko

Publications: Contribution to journalArticlePeer Reviewed

Abstract

Including the effect of lattice anharmonicity on electron-phonon interactions has recently garnered attention due to its role as a necessary and significant component in explaining various phenomena, including superconductivity, optical response, and temperature dependence of mobility. This study focuses on analytically treating the effects of anharmonic electron-phonon coupling on the polaron self-energy, combined with numerical Diagrammatic Monte Carlo (DiagMC) data. Specifically, we incorporate a quadratic interaction into the method of squeezed phonon states, which has proven effective for analytically calculating the polaron parameters. Additionally, we extend this method to nonparabolic finite-width conduction bands while maintaining the periodic translation symmetry of the system. Our results are compared with those obtained from Diagrammatic Monte Carlo, partially reported in a recent study [S. Ragni, Phys. Rev. B 107, L121109 (2023)2469-995010.1103/PhysRevB.107.L121109], covering a wide range of coupling strengths for the nonlinear interaction. Remarkably, our analytic method predicts the same features as the Diagrammatic Monte Carlo simulation.
Original languageEnglish
Article number075107
Number of pages13
JournalPhysical Review B
Volume110
Issue number7
DOIs
Publication statusPublished - 15 Aug 2024

Austrian Fields of Science 2012

  • 103018 Materials physics
  • 103015 Condensed matter
  • 103043 Computational physics

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