Direct determination of spin-orbit interaction coefficients and realization of the persistent spin helix symmetry.
Nat Nanotechnol
; 9(9): 703-9, 2014 Sep.
Article
em En
| MEDLINE
| ID: mdl-25017310
ABSTRACT
The spin-orbit interaction plays a crucial role in diverse fields of condensed matter, including the investigation of Majorana fermions, topological insulators, quantum information and spintronics. In III-V zinc-blende semiconductor heterostructures, two types of spin-orbit interaction--Rashba and Dresselhaus--act on the electron spin as effective magnetic fields with different directions. They are characterized by coefficients α and ß, respectively. When α is equal to ß, the so-called persistent spin helix symmetry is realized. In this condition, invariance with respect to spin rotations is achieved evenâ
in the presence of the spin-orbit interaction, implying strongly enhanced spin lifetimes for spatially periodic spin modes. Existing methods to evaluate α/ß require fitting analyses that often include ambiguity in the parameters used. Here, we experimentally demonstrate a simple and fitting parameter-free technique to determine α/ß and to deduce the absolute values of α and ß. The method is based on the detection of the effective magnetic field direction and the strength induced by the two spin-orbit interactions. Moreover, we observe the persistent spin helix symmetry by gate tuning.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nat Nanotechnol
Ano de publicação:
2014
Tipo de documento:
Article