Electrical control of dynamic spin splitting induced by exchange interaction as revealed by time-resolved Kerr rotation in a degenerate spin-polarized electron gas

Manipulation of the spin degree of freedom has been demonstrated in a spin-polarized electron plasma in a heterostructure by using exchange-interaction-induced 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-interaction-induced spin splitting. The electrical control of it may provide a new effective scheme for manipulating spin-selected transport in spin FET-like devices. Copyright (C) EPLA, 2008.

National Basic Research Program of China 2006CB932801 2007CB924904 Special Research Programs of the Chinese Academy of Sciences The authors would like to thank Z. C. Niu for the sample growth and P. Xu for the sample processing. This work was in part supported by the National Basic Research Program of China No. 2006CB932801 and No. 2007CB924904, and also by Special Research Programs of the Chinese Academy of Sciences.