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Physical Review Letters

Transient Linear Birefringence in GaAs Quantum Wells: Magnetic Field Dependence of Coherent Exciton Spin Dynamics

R.E. Worsley, Nicholas Traynor, Treena Grevatt, Richard T. Harley

Published Apr 22, 1996• 55 citations
Publisher

Abstract

We use reflective probing of transient linear birefringence to study coherent exciton dynamics in GaAs quantum wells as a function of applied magnetic field at low temperatures. The results show the significance of exchange-enhanced exciton spin relaxation for dephasing at zero field. In applied field the signals show background-free quantum beating which gives the exciton g factor and field-dependent dephasing time. The latter is dominated by spin relaxation which shows for the first time the dramatic slowdown predicted in earlier work.

DOI
10.1103/physrevlett.76.3224

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