Optical Response of an Interacting Polaron Gas in Strongly Polar Crystals

Applied Sciences

Georg Kresse¹  Cesare Franchini¹  JozefT. Devreese²  Serghei Klimin²  Jacques Tempere² 

[1] Faculty of Physics, Computational Materials Physics, University of Vienna, A-1090 Vienna, Austria;TQC, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium;

关键词: polaron;    many-polaron systems;    optical response;   

DOI  :  10.3390/app10062059

来源: DOAJ

【 摘 要 】

Optical conductivity of an interacting polaron gas is calculated within an extended random phase approximation which takes into account mixing of collective excitations of the electron gas with longitudinal optical (LO) phonons. This mixing is important for the optical response of strongly polar crystals where the static dielectric constant is rather high, as in the case of strontium titanate. The present calculation sheds light on unexplained features of experimentally observed optical conductivity spectra in n-doped SrTiO ${}_3$ . These features appear to be due to dynamic screening of the electron−electron interaction by polar optical phonons and hence do not require additional mechanisms for their explanation.

【 授权许可】

Unknown