Polaron master equation theory of the quantum-dot Mollow triplet in a semiconductor cavity-QED system
Polaron master equation theory of the quantum-dot Mollow triplet in a semiconductor cavity-QED system
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DOI：
10.1103/physrevb.85.115309
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发表时间：
2012-03
影响因子：
3.7
通讯作者：
C. Roy;S. Hughes
中科院分区：
文献类型：
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作者：
C. Roy;S. Hughes
我们提出了一个全面的理论研究的共振荧光光谱的相干驱动量子点（QD）放置在高量子半导体腔和相互作用的声声子浴。我们在极化子框架中推导了一个量子主方程（ME），其中包括激子-声子和激子-腔耦合到所有阶。在半导体腔QED体系中描述QD的Mollow三重态[j] .光子学报，2006,24（11）。在这里，我们引入了两种ME形式，Nakajima-Zwanzig和时间卷积（TC），它们都是系统-声子-库摄动的二阶。在极化子框架中，这两种ME形式在连续波（cw）驱动场中产生等效的种群动力学和荧光光谱。我们还证明了马尔可夫近似对于计算非相干散射过程是有效的，并且我们随后利用TC ME来探索激子驱动QD的共振荧光光谱。对空腔发射光谱和激子发射光谱进行了研究，发现它们具有定性不同的光谱特征。利用相干驱动场，原子Mollow三重态的众所周知的特性被电子-声-声子散射显著地改变，我们强调了由腔耦合和电子-声子耦合引起的关键效应。举例说明了明显的腔进给和非调和腔QED的情况，我们发现腔耦合敏感地依赖于激子-腔失谐和声子槽的温度。我们展示了mollow -三重态边带的全宽度（线宽）如何随连续波泵的拉比频率的平方而变化。声子介导的腔耦合也有助于Mollow三重态的光谱增宽，这取决于激子-腔失谐和激子-腔耦合速率的强度。最后，我们计算了非共振连续波驱动的荧光光谱，并研究了所得的mollow -三重态线宽。
We present a comprehensive theoretical study of the resonance fluorescence spectra of an coherently-driven quantumdot(QD)placedinsideahigh-Qsemiconductorcavityandinteractingwithanacoustic-phononbath.We derive a quantum master equation (ME) in the polaron frame, which includes exciton-phonon and exciton-cavity couplingtoallorders.Thisworkdetailsandextendsthetheoryusedinarecentpaper[C.RoyandS.Hughes,Phys. Rev. Lett. 106, 247403 (2011)] to describe the QD Mollow triplet in the regime of semiconductor cavity QED. Here, we introduce two ME forms, Nakajima-Zwanzig and time convolutionless (TC), both to second order in the system‐phonon-reservoir perturbation. In the polaron frame, these two ME forms are shown to yield equivalent population dynamics and fluorescence spectra for a continuous wave (cw) driving field. We also demonstrate that a Markov approximation is valid for computing the incoherent scattering processes, and we subsequently exploit the TC ME to explore the resonance fluorescence spectra of an exciton-driven QD. Both cavity-emitted and exciton-emitted spectra are studied, and these are found to have qualitatively different spectral features. Using a coherent driving field, the well-known characteristics of the atomic Mollow triplet are shown to be considerably modified with electron‐acoustic-phonon scattering, and we highlight the key effects arising from both cavity coupling and electron-phonon coupling. Regimes of pronounced cavity feeding and anharmonic cavity QED are exemplified, and we find that the cavity coupling depends sensitively on the exciton-cavity detuning and the temperature of the phonon bath. We show how the full width at half maximum (linewidth) of the Mollow-triplet sidebands varies as a function of the square of the Rabi frequency of the cw pump. Phonon-mediated cavity coupling also contributes to the spectral broadening of the Mollow triplet, depending upon the exciton-cavity detuning and the strength of the exciton-cavity coupling rate. Finally, we calculate the fluorescence spectra for off-resonance cw driving and investigate the resulting Mollow-triplet linewidths.