Quantum Oscillations in the Thermal Conductance of GaAs/AlGaAs Heterostructures.

Magneto-oscillations have, for the first time, been observed in the thermal conductance of GaAs/AlGaAs heterostructures containing two-dimensional electron systems. These oscillations result from a modulation of the thermal phonon lifetime via coupling to the electrons confined in quantum wells near the sample surface. The Landau level quantization of the electronic density of states causes dramatic magneto-oscillations of the strength of this electron-phonon coupling. These thermal conductance measurements provide a new avenue for study of both the high- field density of states and the electron-phonon interaction in these semiconductor systems. *Work performed while at AT&T Bell Laboratories, Murray Hill, NJ. Present address: Sandia National Laboratories, Albuquerque, NM.