Magnetophonon oscillations of thermoelectric power and combined resonance in two-subband electron systems

摘要

By measuring the thermoelectric effect in high-mobility quantum wells withtwo occupied subbands in perpendicular magnetic field, we detect magnetophononoscillations due to interaction of electrons with acoustic phonons. Theseoscillations contain specific features identified as combined resonances causedby intersubband phonon-assisted transitions of electrons in the presence ofLandau quantization. The quantum theory of phonon-drag magnetothermoelectriceffect, generalized to the case of multi-subband occupation, describes ourexperimental findings.