Universal Growth Scheme for Quantum Dots with Low Fine-Structure Splitting at Various Emission Wavelengths
Universal Growth Scheme for Quantum Dots with Low Fine-Structure Splitting at Various Emission Wavelengths
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DOI：
10.1103/physrevapplied.8.014013
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发表时间：
2017-07-14
影响因子：
4.6
通讯作者：
Shields, Andrew J.
中科院分区：
文献类型：
--
作者：
Skiba-Szymanska, Joanna;Stevenson, R. Mark;Shields, Andrew J.
使用光纤基础设施运行量子网络需要单个纠缠光子对的有效来源。量子点在激子本征态之间具有很小的精细结构分裂（FSS），可以产生纠缠光。此外，QD可以被设计成在标准电信波长下发射。为了实现足够的信号强度的应用，量子点已被纳入一维光学微腔。然而，到目前为止，将这些特性结合在一个设备中被证明是难以实现的。在这里，我们介绍了一种增长策略，以实现量子点与小FSS在传统的电信频段，并在一个光学腔。我们的方法采用InAs量子点在（001）衬底上的“液滴外延”。我们表明，该计划提高了72%的对称性的点。此外，我们的技术是通用的，并通过在GaAs上发射类似于900 nm的分子束外延和在InP上发射类似于1550 nm的金属有机气相外延产生低FSS QD，平均FSS比Sttranski-Krastanow QD小4倍。
Efficient sources of individual pairs of entangled photons are required for quantum networks to operate using fiber-optic infrastructure. Entangled light can be generated by quantum dots (QDs) with naturally small fine-structure splitting (FSS) between exciton eigenstates. Moreover, QDs can be engineered to emit at standard telecom wavelengths. To achieve sufficient signal intensity for applications, QDs have been incorporated into one-dimensional optical microcavities. However, combining these properties in a single device has so far proved elusive. Here, we introduce a growth strategy to realize QDs with small FSS in the conventional telecom band, and within an optical cavity. Our approach employs "droplet-epitaxy'' of InAs quantum dots on (001) substrates. We show the scheme improves the symmetry of the dots by 72%. Furthermore, our technique is universal, and produces low FSS QDs by molecular beam epitaxy on GaAs emitting at similar to 900 nm, and metal-organic vapor-phase epitaxy on InP emitting at similar to 1550 nm, with mean FSS 4x smaller than for Stranski-Krastanow QDs.