### Abstract

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 language | English |
---|---|

Pages (from-to) | 144516 |

Number of pages | 9 |

Journal | Physical Review / B |

Volume | 95 |

DOIs | |

Publication status | Published - 2017 |

### Fingerprint

### Keywords

- Superconductivity

### ASJC Scopus subject areas

- Condensed Matter Physics

### Fields of Expertise

- Sonstiges

### Treatment code (Nähere Zuordnung)

- Basic - Fundamental (Grundlagenforschung)

### Cite this

*Physical Review / B*,

*95*, 144516. https://doi.org/10.1103/PhysRevB.95.144516

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

Research output: Contribution to journal › Article › Research › peer-review

*Physical Review / B*, vol. 95, pp. 144516. https://doi.org/10.1103/PhysRevB.95.144516

}

TY - JOUR

T1 - Optical properties of Bogoliubov quasiparticles

AU - Schachinger, Ewald

AU - Carbotte, Jules P.

PY - 2017

Y1 - 2017

N2 - We calculated the optical conductivity $\sigma(T,\Omega)$ of a gas ofBogoliubov quasiparticles (BQP) from their Green's function and theKubo formula. We compare with corresponding normal state (N) andsuperconducting state (SC) results. The superconducting case includesthe dynamic response of the condensate through additional contributionsto the Kubo formula involving the Gor'kov anomalous Green's function.The differences in the optical scattering rate are largest justabove the optical gap and become progressively smaller as the photonenergy is increased or the temperature is raised. Our results arecompared with those obtained using a recently advocated phenomenologicalprocedure for eliminating the effect of the condensate.\cite{dord2014}The $\delta$-function contribution at zero photon energy, proportional tothe superfluid density, is dropped in the real part of the conductivity$[\sigma_1(T,\Omega)]$ and its Kramers-Kronig transform is subtracted fromthe imaginary part $\sigma_2(T,\Omega)$. This results in deviations fromour BQP and superconducting state optical scattering rates even in theregion where these have merged and are, in addition, close to the normalstate result.

AB - We calculated the optical conductivity $\sigma(T,\Omega)$ of a gas ofBogoliubov quasiparticles (BQP) from their Green's function and theKubo formula. We compare with corresponding normal state (N) andsuperconducting state (SC) results. The superconducting case includesthe dynamic response of the condensate through additional contributionsto the Kubo formula involving the Gor'kov anomalous Green's function.The differences in the optical scattering rate are largest justabove the optical gap and become progressively smaller as the photonenergy is increased or the temperature is raised. Our results arecompared with those obtained using a recently advocated phenomenologicalprocedure for eliminating the effect of the condensate.\cite{dord2014}The $\delta$-function contribution at zero photon energy, proportional tothe superfluid density, is dropped in the real part of the conductivity$[\sigma_1(T,\Omega)]$ and its Kramers-Kronig transform is subtracted fromthe imaginary part $\sigma_2(T,\Omega)$. This results in deviations fromour BQP and superconducting state optical scattering rates even in theregion where these have merged and are, in addition, close to the normalstate result.

KW - Superconductivity

U2 - 10.1103/PhysRevB.95.144516

DO - 10.1103/PhysRevB.95.144516

M3 - Article

VL - 95

SP - 144516

JO - Physical Review / B

JF - Physical Review / B

SN - 1098-0121

ER -