Kim Hyochul, Sridharan Deepak, Shen Thomas C, Solomon Glenn S, Waks Edo
Department of Electrical and Computer Engineering, IREAP, University of Maryland, College Park, Maryland 20742, USA and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742, USA.
Opt Express. 2011 Jan 31;19(3):2589-98. doi: 10.1364/OE.19.002589.
We demonstrate strong coupling between two indium arsenide (InAs) quantum dots (QDs) and a photonic crystal cavity by using a magnetic field as a frequency tuning method. The magnetic field causes a red shift of an exciton spin state in one QD and a blue shift in the opposite exciton spin state of the second QD, enabling them to be simultaneously tuned to the same cavity resonance. This method can match the emission frequency of two QDs separated by detunings as large as 1.35 meV using a magnetic field of up to 7 T. By controlling the detuning between the two QDs we measure the vacuum Rabi splitting (VRS) both when the QDs are individually coupled to the cavity, as well as when they are coupled to the cavity simultaneously. In the latter case the oscillator strength of two QDs shows a collective behavior, resulting in enhancement of the VRS as compared to the individual cases. Experimental results are compared to theoretical calculations based on the solution to the full master equation and found to be in excellent agreement.
我们通过使用磁场作为频率调谐方法，展示了两个砷化铟（InAs）量子点（QD）与一个光子晶体腔之间的强耦合。磁场导致一个量子点中激子自旋态发生红移，而第二个量子点中相反激子自旋态发生蓝移，从而使它们能够同时调谐到相同的腔共振。使用高达7 T的磁场，这种方法可以匹配失谐高达1.35 meV的两个量子点的发射频率。通过控制两个量子点之间的失谐，我们测量了量子点分别与腔耦合以及同时与腔耦合时的真空拉比分裂（VRS）。在后一种情况下，两个量子点的振子强度表现出集体行为，与单个情况相比，导致VRS增强。实验结果与基于完整主方程解的理论计算进行了比较，发现两者吻合得非常好。
