Coherent thermoelectric transport in single, double, and U-bend structures

Abstract

Coherent, i.e., ballistic, thermoelectric transport in electron waveguide structures containing right-angle bends in single, double, and U-bend configurations is investigated. A theory based on Green's functions is used to derive the transmission function (and from that the transport coefficients) and allows for the inclusion of realistic models of spatially distributed imperfections. The results for the single and double-bend structures are presented in more detail than elsewhere in the literature. In the U-bend structure, sharp resonances in the stop-band region of the transmission function lead to large-magnitude peaks in the thermopower and consequently a large thermoelectric figure of merit (of order ten in some instances). These properties are still readily apparent even in the presence of moderate edge roughness or Anderson disorder.

Thermoelectric effects in a rectangular Aharonov-Bohm geometry

“…The theory we use is based on the Landauer-Büttiker picture of quantum transport [23][24][25][26] ; see also 2 for further details. The system consists of a device region attached to two semiinfinite leads, each terminating in a reservoir.…”

“…Recent developments have seen growing interest in the realization of small scale electron waveguide structures for specialist thermoelectric applications, based on enhanced performance through tuning electronic transmission together with reducing phonon contributions (see 1,2 and references therein). Such structures include single and multiple bend configurations, leading to the natural question as to the level of performance one might expect from ring geometries.…”