量子点-腔系统耦合强度对非相干抽运的响应

Response of Coupling Strength of Quantum Dot-Cavity System to Incoherent Pump

用量子主方程理论研究了量子点-腔耦合系统。为了说明理论模型,分析了一个量子点微柱腔强耦合(SC)实验。经研究发现耦合系统在稳态时抽运产生一个新的强耦合标准,抽运可以抑制或者增强强耦合;腔发射谱双峰结构并不是强耦合的明确特征,它还依赖于非相干抽运。研究表明,强耦合经常出现变相的单峰而弱耦合(WC)出现双峰结构与系统所控制的参数值密切相关。激子抽运增加时,腔发射谱由双峰逐渐变成增宽的单峰最后变成窄的单峰;腔衰减率增加时,均为双峰结构的腔发射光谱经历了从强耦合到弱耦合的转变。量子点腔失谐系统有效耦合强度与非相干抽运密切相关。

Quantum dot-cavity coupling systems is investigated by using quantum master equation.In order to illustrate theory mode,we analyze a strong coupling（SC） experiment in quantum dot-microcavity system.After studying,we find that the pump in the coupling system yieds new criteria to achieve SC with a steady state,where the incoherent pump hinders or favors SC.Double-peak structure of cavity-emitted spectrum is not an unequivocal signature of strong coupling,which dependes on the incoherent pump.Research shows that SC often appears in disguise of a single peak and double peak in the weak coupling（WC） emission spectrum which closely relates to the parameter values controlled in the system.The spectral shape of the cavity emission changes from double peak to single broad peak then to narrow single peak again with increasing exciton pumping.The cavity-emitted spectra characterized in double-peak experience transition from the SC to WC when the cavity decay rate is increasing.The effective coupling strength of the quantum dot-cavity detuning system relates with incoherent pump closely.