Optical properties of Bogoliubov quasiparticles

Article

关键词: HIGH-TEMPERATURE SUPERCONDUCTIVITY;    ELECTROMAGNETIC PROPERTIES;    SYMMETRY;    CONDUCTIVITY;    ENERGY;   

DOI  :  10.1103/PhysRevB.95.144516

来源: SCIE

【 摘 要 】

We calculate the optical conductivity sigma(T,Omega) of a gas of Bogoliubov quasiparticles from their Green's function and the Kubo formula. We make comparisons with corresponding normal-state and superconducting-state 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. In this procedure 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,sigma)] and its Kramers-Kronig transform is subtracted from the imaginary part sigma(2)(T,Omega). This results in deviations from our Bogoliubov quasiparticle and superconducting-state optical scattering rates even in the region where these have merged and are, in addition, not close to the normal-state result.

【 授权许可】

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