An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
其他凝聚态物理
2009-11-11 v1
摘要
Spin-orbit coupled systems generally break the spin rotation symmetry. However, for a model with equal Rashba and Dresselhauss coupling constant (the ReD model), and for the Dresselhauss model, a new type of SU(2) spin rotation symmetry is discovered. This symmetry is robust against spin-independent disorder and interactions, and is generated by operators whose wavevector depends on the coupling strength. It renders the spin lifetime infinite at this wavevector, giving rise to a Persistent Spin Helix (PSH). We obtain the spin fluctuation dynamics at, and away, from the symmetry point, and suggest experiments to observe the PSH.
引用
@article{arxiv.cond-mat/0606196,
title = {An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System},
author = {B. Andrei Bernevig and J. Orenstein and Shou-Cheng Zhang},
journal= {arXiv preprint arXiv:cond-mat/0606196},
year = {2009}
}
备注
5 pages, 3 figures