Anisotropic plasmons in a two-dimensional electron gas with spin-orbit interaction

Abstract

Spin-orbit coupling-induced anisotropies of plasmon dynamics are investigated in two-dimensional semiconductor
structures. The interplay of the linear Bychkov-Rashba and Dresselhaus spin-orbit interactions
drastically affects the plasmon spectrum: the dynamical structure factor exhibits variations over several decades,
prohibiting plasmon propagation in specific directions. While this plasmon filtering makes the presence
of spin-orbit coupling in plasmon dynamics observable, it also offers a control tool for plasmonic devices.
Remarkably, if the strengths of the two interactions are equal, not only the anisotropy but all the traces of the
linear spin-orbit coupling in the collective response disappear.