Optical conductivity of a strong-coupling polaron

Abstract

The polaron optical conductivity is derived within the strong-coupling expansion, which is asymptotically exact in the strong-coupling limit. The polaron optical conductivity band is provided by the multiphonon optical transitions. The polaron optical conductivity spectra calculated within our analytic strong-coupling approach and the numerically accurate Diagrammatic Quantum Monte Carlo (DQMC) data are in a good agreement with each other at large $\alpha \gtrapprox 9$.Comment: 27 pages, 3 figures. Submitted to Physical Review B on June 12, 2013. A revised paper is in preparation. arXiv admin note: substantial text overlap with arXiv:1012.457