Pure dephasing induced by exciton-phonon interactions in narrow GaAs quantum wells
Pure dephasing induced by exciton-phonon interactions in narrow GaAs quantum wells
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DOI：
10.1016/s0038-1098(98)00461-x
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发表时间：
1998-11-13
影响因子：
2.1
通讯作者：
Wang, HL
中科院分区：
文献类型：
--
作者：
Fan, XD;Takagahara, T;Wang, HL
利用受激光子回波研究了GaAs窄量子威尔斯阱中量子点岛中激子的退相和布居弛豫。这两个密切相关的衰变过程的直接比较揭示了一个纯粹的退相贡献，占主导地位的激子退相在高温下，但不涉及激子布居弛豫。纯退相贡献来自激子态与声学声子的连续体的耦合，并且通过3D量子限制来增强。纯退相速率的大小和温度依赖性都可以用一个理论模型来描述，该模型推广了黄-里斯的F心理论。(C)1998爱思唯尔科技有限公司。保留所有权利。
We investigate both dephasing and population relaxation of excitons localized in quantum dot like islands in narrow GaAs quantum wells by using stimulated photon echoes. A direct comparison of these two closely related decay processes reveals a pure dephasing contribution that dominates excitonic dephasing at elevated temperatures but does not involve exciton population relaxation. The pure dephasing contribution arises from coupling of excitonic states with a continuum of acoustic phonons and is enhanced by 3D quantum confinement. Both the magnitude and the temperature dependence of the pure dephasing rate can be described by a theoretical model that generalizes the Huang-Rhys theory of F-centers. (C) 1998 Elsevier Science Ltd. All rights reserved.