School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
Nano Lett. 2018 Feb 14;18(2):1360-1365. doi: 10.1021/acs.nanolett.7b05075. Epub 2018 Feb 5.
Quantum emitters are an integral component for a broad range of quantum technologies, including quantum communication, quantum repeaters, and linear optical quantum computation. Solid-state color centers are promising candidates for scalable quantum optics due to their long coherence time and small inhomogeneous broadening. However, once excited, color centers often decay through phonon-assisted processes, limiting the efficiency of single-photon generation and photon-mediated entanglement generation. Herein, we demonstrate strong enhancement of spontaneous emission rate of a single silicon-vacancy center in diamond embedded within a monolithic optical cavity, reaching a regime in which the excited-state lifetime is dominated by spontaneous emission into the cavity mode. We observe 10-fold lifetime reduction and 42-fold enhancement in emission intensity when the cavity is tuned into resonance with the optical transition of a single silicon-vacancy center, corresponding to 90% of the excited-state energy decay occurring through spontaneous emission into the cavity mode. We also demonstrate the largest coupling strength (g/2π = 4.9 ± 0.3 GHz) and cooperativity (C = 1.4) to date for color-center-based cavity quantum electrodynamics systems, bringing the system closer to the strong coupling regime.
量子发射器是一系列量子技术的重要组成部分，包括量子通信、量子中继器和线性光学量子计算。由于其长相干时间和小的非均匀展宽，固态色心是可扩展量子光学的有前途的候选者。然而，一旦被激发，色心通常会通过声子辅助过程衰减，限制单光子产生和光子介导纠缠产生的效率。在此，我们展示了嵌入在整体光学腔中的金刚石中单硅空位中心的自发发射率的强烈增强，达到了激发态寿命主要由自发发射到腔模的模式。当腔调谐到与单个硅空位中心的光学跃迁共振时，我们观察到寿命减少 10 倍，发射强度增强 42 倍，对应于 90%的激发态能量通过自发发射到腔模中衰减。我们还展示了迄今为止基于色心的腔量子电动力学系统中最大的耦合强度（g/2π=4.9±0.3GHz）和协同性（C=1.4），使系统更接近强耦合状态。
