We propose a spin-injection method utilizing quantum point contacts (QPCs) fabricated on narrow-gap semiconductors with strong Rashba spin-orbit (SO) interaction. When the conductance through a QPC is quantized in units of 2e 2/h, the current is spin-polarized in the transverse direction to the current even in the absence of magnetic field. The spin polarization, which would be larger than 50% in InGaAs heterostruc - tures, can be detected by connecting the QPC to a ferromagnetic lead. Then the conductance is maximal (minimal) when the magnetization in the lead is parallel or antiparallel (perpendicular) to the spin polarization of the current. The same conductance in the parallel and antiparallel alignments is explained by the Onsager relation, reflecting the fact that the SO interaction does not break the time reversal symmetry.
|Number of pages||4|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - 2006 Dec 1|
|Event||4th International Conference on Physics and Applications of Spin-related Phenomena in Semiconductors, PASPS-IV - Sendai, Japan|
Duration: 2006 Aug 15 → 2006 Aug 18
ASJC Scopus subject areas
- Condensed Matter Physics