Valleytronics, Carrier Filtering and Thermoelectricity in Bismuth: Magnetic Field Polarization Effects

Published

September 25, 2012

Author(s)

Adrian Popescu, Lilia Woods

Abstract

Valley polarization of multi-valleyed materials is of significant interest for potential applications in electronic devices. The main challenge is removing the valley degeneracy in some controllable way. The unique properties of bismuth in terms of its electronic Dirac valley degeneracy and inherent electronic structure anisotropy make this material an excellent system for valleytronics. We demonstrate theoretically that a rotating magnetic field in the binary-bisectrix plane has a profound effect not only on the charge, but also on the thermal transport in the trigonal direction. The rotating field probes the electronic mass anisotropy and tunes the contribution from a particular Dirac valley in the electrical resistivity, Seebeck coefficient, and thermal conductivity at moderate temperatures and field strengths. We further show that this process of field polarization of the transport properties is accompanied by selective filtering of the carriers type providing further opportunities for thermoelectric transport control.

Citation

Advanced Functional Materials

Volume

22

Issue

18

Pub Type

Journals

Download Paper

https://doi.org/10.1002/adfm.20

Keywords

bismuth, thermoelectrics, valleytronics, thermal transport

Citation

Popescu, A. and Woods, L. (2012), Valleytronics, Carrier Filtering and Thermoelectricity in Bismuth: Magnetic Field Polarization Effects, Advanced Functional Materials, [online], https://doi.org/10.1002/adfm.20 (Accessed October 6, 2024)