Electron-spin beat susceptibility of excitons in semiconductor quantum wells.
Recent time-resolved differential transmission and Faraday rotation measurements of long-lived electron-spin coherence in quantum wells displayed intriguing parametric dependencies. For their understanding we formulate a microscopic theory of the optical response of a gas of optically incoherent excitons whose constituent electrons retain spin coherence, under a weak magnetic field applied in the quantum well's plane. We define a spin beat susceptibility and evaluate it in linear order of the exciton density. Our results explain the many-body physics underlying the basic features observed in the experimental measurements.
College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA.
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Kwong
Stefan
S
Schumacher
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R
Binder