Satellites in the photoemission spectra of A3C60 (A=K and Rb).

Abstract

The high-resolution photoemission spectral profiles of the conduction bands of ${\mathrm{K}}_{3}$${\mathrm{C}}_{60}$ and ${\mathrm{Rb}}_{3}$${\mathrm{C}}_{60}$ recorded at 10 K exhibit fine structure not observed at higher temperatures. Calculations of the effects of electron-boson coupling in ${\mathit{A}}_{3}$${\mathrm{C}}_{60}$ within a simple model demonstrate that the features in the low-temperature photoemission spectral weight are consistent with satellites due to phonons and the charge-carrier plasmon. Possible causes of the observed temperature dependence of the conduction-band spectral weight are discussed.