Emergence of the persistent spin helix in semiconductor quantum wells
| dc.creator | Koralek, Jake D. | |
| dc.creator | Weber, Chris | |
| dc.creator | Orenstein, Joe | |
| dc.creator | Bernevig, Andrei | |
| dc.creator | Zhang, Shou-Cheng | |
| dc.creator | Mack, Shawn | |
| dc.creator | Awschalom, David | |
| dc.date | 2009-03-26 | |
| dc.date | 2009-03-28 | |
| dc.date.accessioned | 2026-07-07T12:58:56Z | |
| dc.date.available | 2026-07-07T12:58:56Z | |
| dc.description | According to Noethers theorem, for every symmetry in nature there is a corresponding conservation law. For example, invariance with respect to spatial translation corresponds to conservation of momentum. In another well-known example, invariance with respect to rotation of the electrons spin, or SU(2) symmetry, leads to conservation of spin polarization. For electrons in a solid, this symmetry is ordinarily broken by spin-orbit coupling, allowing spin angular momentum to flow to orbital angular momentum. However, it has recently been predicted that SU(2) can be achieved in a two-dimensional electron gas, despite the presence of spin-orbit coupling. The corresponding conserved quantities include the amplitude and phase of a helical spin density wave termed the persistent spin helix. SU(2) is realized, in principle, when the strength of two dominant spin-orbit interactions, the Rashba (strength parameterized by α) and linear Dresselhaus (β_1), are equal. This symmetry is predicted to be robust against all forms of spin-independent scattering, including electron-electron interactions, but is broken by the cubic Dresselhaus term (β_3) and spin-dependent scattering. When these terms are negligible, the distance over which spin information can propagate is predicted to diverge as αapproaches β_1. Here we observe experimentally the emergence of the persistent spin helix in GaAs quantum wells by independently tuning αand β_1. Using transient spin-grating spectroscopy, we find a spin-lifetime enhancement of two orders of magnitude near the symmetry point......... | |
| dc.description | Will be published in Nature on April 2, 2009 | |
| dc.identifier | https://arxiv.org/abs/0903.4709 | |
| dc.identifier | http://arxiv.org/abs/0903.4709 | |
| dc.identifier | Nature 458, 610-613 (2009) | |
| dc.identifier | doi:10.1038/nature07871 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/225414 | |
| dc.subject | Materials Science | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.title | Emergence of the persistent spin helix in semiconductor quantum wells | |
| dc.type | text |