Abstract
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. © 2009 The American Physical Society.
| Original language | English |
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| Article number | 056405 |
| Journal | Physical Review Letters |
| Volume | 103 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 6 Aug 2009 |