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Bibliographic Details
Main Authors: Karuzin, Daniil K., Skvortsov, Mikhail A.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2511.23431
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author Karuzin, Daniil K.
Skvortsov, Mikhail A.
author_facet Karuzin, Daniil K.
Skvortsov, Mikhail A.
contents We develop a theory for the plasmon spectrum in dirty superconductors across the entire temperature range. Starting with the microscopic Keldysh sigma model description, we link the plasmon dispersion $ω(q)$ to the optical conductivity $σ(ω,T)$ of a superconductor, which requires analytical continuation to the lower half-plane of complex frequency. This approach reveals a discontinuity at the superconducting transition: a jump in both the real and imaginary parts of $ω(q)$ at $T_c$. For any temperature below $T_c$, the plasmon dispersion terminates at a critical wave vector $q_c(T)$ where plasmons remains undamped, with weakly $T$-dependent $ω[q_c(T)] \approx 2Δ(0)$. Plasmons significantly attenuate only within a narrow 5% temperature window near $T_c$, with the propagating mode recovering at large $q$.
format Preprint
id arxiv_https___arxiv_org_abs_2511_23431
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Plasmon excitations and their attenuation in dirty superconductors
Karuzin, Daniil K.
Skvortsov, Mikhail A.
Superconductivity
We develop a theory for the plasmon spectrum in dirty superconductors across the entire temperature range. Starting with the microscopic Keldysh sigma model description, we link the plasmon dispersion $ω(q)$ to the optical conductivity $σ(ω,T)$ of a superconductor, which requires analytical continuation to the lower half-plane of complex frequency. This approach reveals a discontinuity at the superconducting transition: a jump in both the real and imaginary parts of $ω(q)$ at $T_c$. For any temperature below $T_c$, the plasmon dispersion terminates at a critical wave vector $q_c(T)$ where plasmons remains undamped, with weakly $T$-dependent $ω[q_c(T)] \approx 2Δ(0)$. Plasmons significantly attenuate only within a narrow 5% temperature window near $T_c$, with the propagating mode recovering at large $q$.
title Plasmon excitations and their attenuation in dirty superconductors
topic Superconductivity
url https://arxiv.org/abs/2511.23431