Phonon emission by a hot two-dimensional electron gas in a quantizing magnetic field

Abstract

A detailed analysis is made of the acoustic phonon emission spectrum of a heated 2DEG in a (0 0 1) n-Si inversion layer, when a quantizing magnetic field B is applied perpendicular to the layer. Particular attention is given to the case of high magnetic fields when only a few Landau levels are occupied. The emitted power is then quasimonochromatic at the cyclotron frequency and the angular distribution shows a sharp maximum at a propagation angle ϑ m to the field, given by sin ϑ m ∼ m ∗v s/( 1 2 eB h ̷ ) 1 2 , where m ∗ is the effective mass and v s the sound velocity. Both longitudinal and transverse modes are considered and the transition to zero field is discussed.