Method and apparatus for generating and controlling spin propagation using one or more coherent light beams
US6643047B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 22, 2002 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Apr 3, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/0338
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention uses quantum interference of one and two photon absorption from a multiple color fields to optically inject ballistic spin currents in unbiased photoconductors. The spin currents can be generated with and without an accompanying electrical current and can be controlled using the relative phase of the colors. In one aspect of the there is provided a method of generating spin currents in a photoconductor material comprising producing a first coherent light beam having a first frequency &ohgr;1 and a second coherent light beam having a frequency twice the first frequency 2&ohgr;1, polarizing the first and second coherent light beams to have a preselected polarization with respect to each other, and simultaneously irradiating a selected region of the photoconductor material with the first coherent light beam and the second coherent light beam to generate a spin current in the photoconductor. When the photoconductor has a noncentrosymmetric zincblende (Td symmetry) crystal structure a single coherent light beam can be used to obtain pure spin currents and mixed electrical and spin, currents may be produced when the photoconductor has a wurtzite structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.