J Beyer et al 2009 Nanotechnology 20 375401 doi:10.1088/0957-4484/20/37/375401
J Beyer1, I A Buyanova1, S Suraprapapich2, C W Tu2 and W M Chen1
Show affiliationsOptical spin injection is studied in novel laterally-arranged self-assembled InAs/GaAs quantum dot structures, by using optical orientation measurements in combination with tunable laser spectroscopy. It is shown that spins of uncorrelated free carriers are better conserved during the spin injection than the spins of correlated electrons and holes in an exciton. This is attributed to efficient spin relaxation promoted by the electron–hole exchange interaction of the excitons. Our finding suggests that separate carrier injection, such as that employed in electrical spin injection devices, can be advantageous for spin conserving injection. It is also found that the spin injection efficiency decreases for free carriers with high momentum, due to the acceleration of spin relaxation processes.
Issue 37 (16 September 2009)
Received 4 May 2009, in final form 28 July 2009
Published 26 August 2009
J Beyer et al 2009 Nanotechnology 20 375401
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