Thermo emf in a two-dimensional electron-hole system in HgTe quantum wells in the presence of magnetic field. The role of the diffusive and the phonon-drag contributions
E. B. Olshanetsky1, Z. D. Kvon1,2, G. M. Gusev3, M. V. Entin1, L.I. Magarill1, and N. N. Mikhailov1
1Institute of Semiconductor Physics, Novosibirsk 630090, Russia
E-mail: kvon@thermo.isp.nsc.ru
2Novosibirsk State University, Novosibirsk 630090, Russia
3Instituto de Fsica da Universidade de São Paulo, São Paulo 135960-170, SP, Brazil
pos Анотація:597
Received September 09, 2020, published online November 24, 2020
Abstract
We present an experimental study of the thermo emf of a two-dimensional electron-hole system in a 21 nm HgTe quantum well in the presence of magnetic field. The first experimental observation of Nernst–Ettingshausen effect in a 2D semimetal is reported. The comparison between theory and experiment shows that the thermo emf is determined by two contributions: the diffusion and the phonon drag, with the latter contribution several times greater than the first. The conclusion is drawn about the important role of electron-hole scattering in the formation of both thermoelectric power mechanisms.
Key words: quantum well, 2D semimetal, diffusion, phonon drag.
