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Past Events
Spin Photocurrent as well as the Converse Spin Polarization Induced by Current In Ingaas/Inalas Two-Dimensional Electron Gas
| Speaker: | Prof. W.K. Ge |
| Time: | 4:00-5:00 p.m. |
| Date: | February 4, 2009 (Wed) |
| Affiliation: | Physics Department, Tsinghua University, Beijing, China Physics Department, Sun Yat-Sen University, Guangzhou, China |
| Venue: | Room 522, 5/F, Chong Yuet Ming Physics Building, HKU |
Abstract:
The structure inversion asymmetry induced spin-orbit coupling in an InGaAs/InAlAs two dimensional electron gas system has been depicted by beatings of the Shubnikov-de Haas oscillations, and most impressively revealed by both the spin photocurrent and its converse process of current-induced spin polarization. For the conversion of electron spin into directed electric current, the optical excitation with band-to-band transitions was employed using oblique incident circularly polarized laser, which showed more than 2 orders enlarged effect in comparison to similar effect induced by inter-subband excitations. Kerr effect clearly demonstrated the capability that current could conversely induce spin polarization in a two-dimensional electron gas system implying the potential of a spin source for spintronic devices.
Coffee and tea will be served 20 minutes prior to the seminar.