Optical properties of Bogoliubov quasiparticles

Ewald Schachinger, Jules P. Carbotte

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We calculated the optical conductivity $\sigma(T,\Omega)$ of a gas of
Bogoliubov quasiparticles (BQP) from their Green's function and the
Kubo formula. We compare with corresponding normal state (N) and
superconducting state (SC) results. The superconducting case includes
the dynamic response of the condensate through additional contributions
to the Kubo formula involving the Gor'kov anomalous Green's function.
The differences in the optical scattering rate are largest just
above the optical gap and become progressively smaller as the photon
energy is increased or the temperature is raised. Our results are
compared with those obtained using a recently advocated phenomenological
procedure for eliminating the effect of the condensate.\cite{dord2014}
The $\delta$-function contribution at zero photon energy, proportional to
the superfluid density, is dropped in the real part of the conductivity
$[\sigma_1(T,\Omega)]$ and its Kramers-Kronig transform is subtracted from
the imaginary part $\sigma_2(T,\Omega)$. This results in deviations from
our BQP and superconducting state optical scattering rates even in the
region where these have merged and are, in addition, close to the normal
state result.
Original languageEnglish
Pages (from-to)144516
Number of pages9
JournalPhysical Review / B
Volume95
DOIs
Publication statusPublished - 2017

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Green's function
condensates
Green's functions
Optical properties
Scattering
Optical conductivity
Delta functions
optical properties
conductivity
delta function
dynamic response
scattering
Dynamic response
Photons
Gases
deviation
photons
gases
Temperature
temperature

Keywords

  • Superconductivity

ASJC Scopus subject areas

  • Condensed Matter Physics

Fields of Expertise

  • Sonstiges

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

Cite this

Optical properties of Bogoliubov quasiparticles. / Schachinger, Ewald; Carbotte, Jules P.

In: Physical Review / B, Vol. 95, 2017, p. 144516.

Research output: Contribution to journalArticleResearchpeer-review

Schachinger, Ewald ; Carbotte, Jules P. / Optical properties of Bogoliubov quasiparticles. In: Physical Review / B. 2017 ; Vol. 95. pp. 144516.
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