A quantum dot single-photon source with on-the-fly all-optical polarization control and timed emission.
A quantum dot single-photon source with on-the-fly all-optical polarization control and timed emission.
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DOI：
10.1038/ncomms9473
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发表时间：
2015-10-05
影响因子：
16.6
通讯作者：
Schumacher S
中科院分区：
文献类型：
--
作者：
Heinze D;Breddermann D;Zrenner A;Schumacher S
单光子源是量子信息科学应用的关键因素。在可用的不同来源中，半导体量子点以其在半导体片上解决方案中的可集成性和可按需触发光子发射的潜力而脱颖而出。通常，光子是从单激子基态发射的。光子的偏振和发射时间要么是概率的，要么是由系统的电子特性预先决定的。本文研究了双激子的直接双光子发射。双光子发射是通过激光脉冲驱动系统进入带隙内的虚态来实现的。从这个中间状态，我们感兴趣的单个光子被自发地发射出来。我们表明，通过这种高阶跃迁的发射提供了一种产生单个光子的通用方法。通过驱动激光脉冲，可以实时控制光子的偏振态、频率和发射时间。单光子源在量子信息领域具有重要的应用价值。在这里，作者利用半导体量子点从双激子态到基态的高阶跃迁来发射单光子，并对其频率、偏振和发射时间进行全光控制。
Sources of single photons are key elements for applications in quantum information science. Among the different sources available, semiconductor quantum dots excel with their integrability in semiconductor on-chip solutions and the potential that photon emission can be triggered on demand. Usually, the photon is emitted from a single-exciton ground state. Polarization of the photon and time of emission are either probabilistic or pre-determined by electronic properties of the system. Here, we study the direct two-photon emission from the biexciton. The two-photon emission is enabled by a laser pulse driving the system into a virtual state inside the band gap. From this intermediate state, the single photon of interest is then spontaneously emitted. We show that emission through this higher-order transition provides a versatile approach to generate a single photon. Through the driving laser pulse, polarization state, frequency and emission time of the photon can be controlled on-the-fly. Single photon sources are important for applications in quantum information. Here, the authors exploit higher-order transitions from a biexciton state to the ground state of a semiconductor quantum dot to emit single photons with all-optical control of their frequency, polarization and emission time.