Spin orbit interaction and zitterbewegung in symmetric wells

TL;DR

This paper explores a newly identified spin-orbit coupling in symmetric quantum wells with multiple subbands, revealing its connection to zitterbewegung, a trembling motion analogous to relativistic electrons, and provides explicit expressions for this phenomenon.

Contribution

It introduces a novel inter-subband-induced spin-orbit coupling in symmetric wells and derives explicit formulas for the associated zitterbewegung in spin space.

Findings

Identification of a new spin-orbit coupling in symmetric wells

Derivation of explicit zitterbewegung expressions in spin space

Demonstration of cycloidal motion without magnetic fields

Abstract

Recently, we have introduced a novel inter-subband-induced spin-orbit (s-o) coupling [Phys. Rev. Lett. 99, 076603 (2007); cond-mat/0607218] arising in \textit{symmetric} wells with at least two subbands. This new s-o coupling gives rise to an usual zitterbewegung -- i.e. the semiconductor analog to the relativistic trembling motion of electrons -- with cycloidal motion without magnetic fields. Here we complement these findings by explicitly deriving expressions for the corresponding zitterbewegung in spin space.