В среду, 18 августа 2021, 15.00 в КЗ ТК состоится Семинар отдела физики поверхности

A. D. Levine
(University Sao-Paolo)

Phonon drag thermoelectric phenomena in mesoscopic two-dimensional conductors

In mesoscopic channels, whose width L is smaller than the mean free path length, the drag-induced Nernst voltage can be comparable with the Seebeck one, which is never the case in macroscopic samples. We have studied thermo induced voltages in the samples based on the high-quality GaAs quantum wells. In our work, we have obtained an unusual thermoelectric response attributed to the phonon drag mechanism. To explain the observation of a large Nernst effect in the classical transport region, we present a theoretical model based on the assumption that the phonon distribution function is considerably different from the weakly non-equilibrium distribution usually applied for a theoretical description of the phonon drag thermoelectricity. A good agreement between experimental and theoretical suppression of the Nernst voltage by temperature is obtained.