Electrical control of dynamic spin splitting induced by exchange interaction as revealed by time-resolved Kerr rotation in a degenerate spin-polarized electron gasF. Zhang, H. Z. Zheng, Y. Ji, J. Liu and G. R. Li
State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences - P.O. Box 912, Beijing 100083, China
received 27 March 2008; accepted in final form 25 June 2008; published August 2008
published online 6 August 2008
Manipulation of the spin degree of freedom has been demonstrated in a spin-polarized electron plasma in a heterostructure by using exchange-interactioninduced dynamic spin splitting rather than the Rashba and Dresselhaus types, as revealed by time-resolved Kerr rotation. The measured spin splitting increases from 0.256 meV to 0.559 meV as the bias varies from - 0.3 V to -0.6 V. Both the sign switch of the Kerr signal and the phase reversal of Larmor precessions have been observed with biases, which all fit into the framework of exchange-interactioninduced spin splitting. The electrical control of it may provide a new effective scheme for manipulating spin-selected transport in spin FET-like devices.
72.25.Fe - Optical creation of spin polarized carriers.
72.25.Dc - Spin polarized transport in semiconductors.
78.47.-p - Spectroscopy of solid state dynamics.
© EPLA 2008