Pseudospin transfer torques and the effect of disorder in semiconductor electron bilayers

We use self-consistent quantum transport theory to investigate the influence of electron-electron interactions on interlayer transport in semiconductor electron bilayers in the absence of an external magnetic fi eld. We conclude that, even though spontaneous pseudospin order does not occur at zero field, interaction-enhanced quasiparticle tunneling amplitudes and pseudospin transfer torques do alter tunneling I-V characteristics, and can lead to time-dependent response to a dc bias voltage. In addition, we study the eff ects of disorder on the interlayer transport properties of disordered semiconductor bilayers. We find that the addition of material disorder to the system affects interlayer interactions leading to signifi cant deviations in the interlayer transfer characteristics. In particular, we find that disorder decreases and broadens the tunneling peak, eff ectively reducing the interacting system to a non-interacting system. Our results suggest that the experimental observation of interaction-enhanced interlayer transport in semiconductor bilayers requires materials with mean-free paths larger than the spatial extent of the system.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Kim, Youngseok

Contributors dc:contributor

• Gilbert, Matthew J.

• Pseudospin ferromagnetism
• semiconductor bilayer

Statement dc:rights

• Copyright 2012 Youngseok Kim

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/31211

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/31211