Signatures of Quantum Coherences in Rydberg Excitons
Signatures of Quantum Coherences in Rydberg Excitons
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DOI：
10.1103/physrevlett.117.133003
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发表时间：
2016-09-22
影响因子：
8.6
通讯作者：
Scheel, S.
中科院分区：
文献类型：
--
作者：
Gruenwald, P.;Assmann, M.;Scheel, S.
单个粒子的相干光学控制已经在原子和半导体量子点中得到了证明。在这里，我们证明了块状Cu2 O中半导体里德伯激子中量子相干效应的出现。由于两个相邻里德伯激子态之间的光谱接近，单频激光器可以泵浦两个共振，而失谐的耗散很小。因此，额外的共振出现在吸收光谱中，对应于由耦合到激子真空的两个里德伯激子能级组成的修饰态，形成V型三能级系统，但仅由一个激光光源驱动。我们表明，在这个系统中的纯退相的水平是非常低的。这些观测是在大块半导体中实现相干控制量子技术的关键一步。
Coherent optical control of individual particles has been demonstrated both for atoms and semiconductor quantum dots. Here we demonstrate the emergence of quantum coherent effects in semiconductor Rydberg excitons in bulk Cu2O. Because of the spectral proximity between two adjacent Rydberg exciton states, a single-frequency laser may pump both resonances with little dissipation from the detuning. As a consequence, additional resonances appear in the absorption spectrum that correspond to dressed states consisting of two Rydberg exciton levels coupled to the excitonic vacuum, forming a V-type three-level system, but driven only by one laser light source. We show that the level of pure dephasing in this system is extremely low. These observations are a crucial step towards coherently controlled quantum technologies in a bulk semiconductor.