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arXiv · 2409.19562

Instability of metals with respect to strong electron-phonon interaction

Emil A. Yuzbashyan·Boris L. Altshuler·Aniket Patra
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Abstract

We show that thermal equilibrium between conduction electrons and phonons becomes kinetically unstable when the renormalized electron-phonon coupling exceeds a certain threshold. We prove that negative electronic specific heat, $C_\mathrm{el} < 0$, is sufficient to trigger the instability. Specifically, the instability sets in as soon as the quasiparticle weight becomes negative over a range of energies, even before $C_\mathrm{el}$ turns negative. This is an inherently nonequilibrium phenomenon, occurring prior to the formation of any equilibrium phase. Depending on the system, it can proceed along different pathways, ultimately resulting in a structural transition to an insulating or metallic state.

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Emil A. Yuzbashyan, Boris L. Altshuler, Aniket Patra. 2024-09-29. Instability of metals with respect to strong electron-phonon interaction. https://doi.org/10.1103/sf5p-2g5l

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