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

TL;DR

This paper investigates magnetophonon oscillations and combined resonances in thermoelectric power within two-subband electron systems, revealing how intersubband phonon interactions influence thermoelectric effects under magnetic fields.

Contribution

It introduces a quantum theory for phonon-drag magnetothermoelectric effects in multi-subband systems, explaining experimental observations of magnetophonon oscillations and combined resonances.

Findings

Detection of magnetophonon oscillations in thermoelectric power.

Identification of combined resonances from intersubband phonon-assisted transitions.

Theoretical model successfully explains experimental data.

Abstract

By measuring the thermoelectric effect in high-mobility quantum wells with two occupied subbands in perpendicular magnetic field, we detect magnetophonon oscillations due to interaction of electrons with acoustic phonons. These oscillations contain specific features identified as combined resonances caused by intersubband phonon-assisted transitions of electrons in the presence of Landau quantization. The quantum theory of phonon-drag magnetothermoelectric effect, generalized to the case of multi-subband occupation, describes our experimental findings.