An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System

Journal Article · Wed Feb 10 00:00:00 EST 2010 · Submitted to Physical Review Letters

OSTI ID:972232

Bernevig, Andrei

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 [110] 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.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 972232
• Report Number(s): SLAC-PUB-13915; TRN: US201006%%1002
• Journal Information: Submitted to Physical Review Letters, Journal Name: Submitted to Physical Review Letters
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COUPLING CONSTANTS
FLUCTUATIONS
LIFETIME
ROTATION
SPIN
SYMMETRY
MATSCI