Volume 83, Number 4, August 2008
Article Number 47006
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 06 August 2008
EPL, 83 (2008) 47006
DOI: 10.1209/0295-5075/83/47006

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

F. 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-interaction$\hbox{--} $induced dynamic spin splitting rather than the Rashba and Dresselhaus types, as revealed by time-resolved Kerr rotation. The measured spin splitting increases from 0.256 meV to 0.559 meV as the bias varies from - 0.3 V to -0.6 V. Both the sign switch of the Kerr signal and the phase reversal of Larmor precessions have been observed with biases, which all fit into the framework of exchange-interaction$\hbox{--} $induced 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