Institute of Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland.
Phys Rev Lett. 2009 Nov 13;103(20):207403. doi: 10.1103/PhysRevLett.103.207403. Epub 2009 Nov 12.
In a coupled quantum-dot-nanocavity system, the photoluminescence from an off-resonance cavity mode exhibits strong quantum correlations with the quantum-dot transitions, even though its autocorrelation function is classical. Using new pump-power dependent photon-correlation measurements, we demonstrate that this seemingly contradictory observation that has so far defied an explanation stems from cascaded cavity photon emission in transitions between excited multiexciton states. The mesoscopic nature of quantum-dot confinement ensures the presence of a quasicontinuum of excitonic transitions, part of which overlaps with the cavity resonance.
在耦合量子点-纳米腔系统中，即使腔模的发射光谱的自相关函数是经典的，其与量子点跃迁的光致发光也表现出很强的量子相关性。利用新的依赖于泵浦功率的光子相关测量，我们证明了这一似乎矛盾的观察结果，迄今为止，这一观察结果一直没有得到解释，其源于在激发多激子态之间的跃迁中级联腔光子发射。量子点限制的介观性质确保了激子跃迁的准连续存在，其中一部分与腔共振重叠。
