Magneto-acoustic absorption by the electron-hole liquid in stressed germanium

Abstract

We report the observation of magneto-acoustic absorption by the electron-hole liquid in a potential well in stressed germanium. This experiment confirms the metallic character of the liquid and yields direct values for the electron Fermi level ϵ F = (2.6±0.1) meV and inter-carrier collision time τ = (6.0±0.5) × 10 -11 sec at 1.8 K under a stress of approximately 5 kg/mm 2. From ϵ F we deduce an electron density of n = (6.2) ± 0.4) × 10 16 cm -3 at 1.8 K.