AI 中文总结
研究利用半导体量子点生成线性光子簇态的不同方案，通过理论比较四种方案，考量不同误差机制影响，给出基于自旋相干时间等因素在磁场驱动与光学控制协议间选择的 regime 图。
AI 中文摘要
光子图态是基于测量的量子信息处理的关键资源态。由于半导体量子点是优秀的确定性光子发射器，已提出几种使用它们生成线性簇态的协议，要么基于弱磁场中空穴或电子自旋的恒定进动，要么基于强磁场中的光学自旋控制。我们从理论上比较了四种此类方案，分别针对一系列腔环境和自旋相干时间使用偏振或时间-bin编码。特别地，我们使用自旋控制、激发和发射动力学以及声子浴的微观模型研究不同误差机制如何影响不同方案。我们发现基于自旋进动的方案在强腔增强下扩展性良好且对声子诱导的退相干具有天然鲁棒性，而使用光学自旋控制的方案在较低自旋相干时间下能表现良好且强烈依赖于腔诱导循环跃迁的协同性。我们的结果提供了一个 regime 图，用于根据自旋相干时间、珀塞尔增强和对不需要的衰减通道的抑制在磁场驱动和光学控制协议之间进行选择。
英文摘要
Photonic graph states are key resource states for measurement based quantum information processing. As semiconductor quantum dots are excellent deterministic photon emitters, several protocols using them for the generation of linear cluster states have been proposed, either based on constant precession of a hole or electron spin in a weak magnetic field, or based on optical spin control, in a stronger magnetic field. We theoretically compare four such schemes, using polarization or time-bin encoding, respectively, for a range of cavity environments and spin coherence times. In particular we study how different error mechanisms affect the different schemes, using a microscopic model of the spin control, the excitation and emission dynamics, and of the phonon bath. We find the spin-precession based schemes to scale well with strong cavity enhancement and to be naturally robust against phonon-induced decoherence, while the schemes using optical spin control can perform well for lower spin coherence times and are strongly dependent on the cooperativity of the cavity induced cycling transition. Our results provide a regime map for choosing between magnetic-field-driven and optically controlled protocols depending on spin coherence time, Purcell enhancement, and suppression of unwanted decay channels.
Comments15 pages, 9 figures
