H. Q. Ye, G. Wang, B. L. Liu, Z. W. Shi, W. X. Wang, C. Fontaine, A. Balocchi, T. Amand, D. Lagarde, P. Renucci, X. Marie
The electron spin dynamics is studied by time-resolved Kerr rotation in GaAs/AlGaAs quantum wells embedded in NIP structures grown on (111)A or (111)B-oriented substrates. In both cases the spin lifetimes are significantly increased by applying an external electric field but this field has to point along the growth direction for structures grown on (111)A and opposite to it for the ones grown on (111)B . This extended electron spin lifetime is the result of the suppression of the D'yakonov-Perel spin relaxation mechanism due to the cancellation effect of the internal Dresselhaus term with the external electric field induced Rashba one, both governing the conduction band spin-orbit splitting. These results demonstrate the key role played by the polar character of the (111) surfaces on the electron spin dynamics.
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http://arxiv.org/abs/1204.0154
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