Deterministic Photon Pairs and Coherent Optical Control of a Single Quantum Dot
Deterministic Photon Pairs and Coherent Optical Control of a Single Quantum Dot
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DOI：
10.1103/physrevlett.110.135505
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发表时间：
2013-03-26
影响因子：
8.6
通讯作者：
Weihs, Gregor
中科院分区：
文献类型：
--
作者：
Jayakumar, Harishankar;Predojevic, Ana;Weihs, Gregor
量子点中半导体激子的强约束产生了类似原子的行为。这种结构的全部好处在共振激发中得到了最好的观察，在共振激发中激发态可以被确定性地填充和相干地操纵。由于较大的折射率和器件的几何形状，在III/V自组装量子点中观察无激光散射的共振激发发射仍然具有挑战性。本文利用双激子结合能，利用InAs/GaAs量子点的双光子共振激发，制备了极干净的单光子源。我们观察到激发激光和多光子发射完全被抑制。此外，我们对基双激子态量子比特进行了全相干控制，并使用全光回波技术观察了延长的相干时间。该系统的确定性相干光子对的产生使得该系统适合于时间阱纠缠的产生和不同源光子相互作用的实验。DOI: 10.1103 / PhysRevLett.110.135505
The strong confinement of semiconductor excitons in a quantum dot gives rise to atomlike behavior. The full benefit of such a structure is best observed in resonant excitation where the excited state can be deterministically populated and coherently manipulated. Because of the large refractive index and device geometry it remains challenging to observe resonantly excited emission that is free from laser scattering in III/V self-assembled quantum dots. Here we exploit the biexciton binding energy to create an extremely clean single photon source via two-photon resonant excitation of an InAs/GaAs quantum dot. We observe complete suppression of the excitation laser and multiphoton emissions. Additionally, we perform full coherent control of the ground-biexciton state qubit and observe an extended coherence time using an all-optical echo technique. The deterministic coherent photon pair creation makes this system suitable for the generation of time-bin entanglement and experiments on the interaction of photons from dissimilar sources. DOI: 10.1103/PhysRevLett.110.135505