V. Eyert — Page 3 | Searcharxiv

arXiv1999

Phonon line shape in disordered A3C60 (A= K, Rb)

We present a calculation of the Hg phonon self-energy for a model of A3C60 (A= K, Rb). The orientational disorder of the C60 molecules is included, and the lowest order self-energy diagram is considered. The calculations illustrate that due to the violation of momentum conservation by the orientational disorder, Raman scattering can measure the decay of a phonon in an electron-hole pair, allowing the estimate of the electron-phonon coupling from such experiments. Comparison with experimental line shapes further provides support for a local correlation of the molecular orientations, with neighboring molecules preferentially having orientations differing by a 90 degree rotation.

cond-mat.mtrl-sci↗

arXiv1997

Optical conductivity in A3C60 (A=K, Rb)

We study the optical conductivity in A3C60 (A =K, Rb). The effects of the electron-phonon interaction is included to lowest order in the coupling strength lambda. It is shown that this leads to a narrowing of the Drude peak by a factor 1+lambda and a transfer of weight to a mid-infrared peak at somewhat larger energies than the phonon energy. Although this goes in the right direction, it is not sufficient to describe experiment.

cond-mat.str-el↗