A light-hole exciton in a quantum dot
A light-hole exciton in a quantum dot
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DOI：
10.1038/nphys2799
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发表时间：
2014-01-01
期刊：
影响因子：
19.6
通讯作者：
Schmidt, O. G.
中科院分区：
文献类型：
--
作者：
Huo, Y. H.;Witek, B. J.;Schmidt, O. G.
光空穴激子是由单个电子与单个光空穴结合形成的准粒子。这种基本激发，如果被限制在半导体量子点内，在量子信息科学和技术中可能是有利的。然而，到目前为止，很难接近它，因为传统量子点中的限制和应变有利于具有主要重空穴特征的基态单粒子空穴。在这里，我们演示了通过施加弹性应力到初始无应变的量子点的光空穴激子基态的创建。它的签名是明显有别于著名的重空穴激子，并由三个正交偏振明亮的光学跃迁和精细结构分裂的面内和面外组件之间的数百微电子伏特。这项工作为探索量子技术中三维受限光空穴态的基本性质和潜在相关性铺平了道路。
A light-hole exciton is a quasiparticle formed from a single electron bound to a single light hole. This type of fundamental excitation, if confined inside a semiconductor quantum dot, could be advantageous in quantum information science and technology. However, it has been difficult to access it so far, because confinement and strain in conventional quantum dots favour a ground-state single-particle hole with a predominantly heavy-hole character. Here we demonstrate the creation of a light-hole exciton ground state by applying elastic stress to an initially unstrained quantum dot. Its signature is clearly distinct from that of the well-known heavy-hole exciton and consists of three orthogonally polarized bright optical transitions and a fine-structure splitting of hundreds of microelectronvolts between in-plane and out-of-plane components. This work paves the way for the exploration of the fundamental properties and of the potential relevance of three-dimensionally confined light-hole states in quantum technologies.