Characterization of spectral diffusion by slow-light photon-correlation spectroscopy
Characterization of spectral diffusion by slow-light photon-correlation spectroscopy
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DOI：
10.1103/physrevb.101.161401
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发表时间：
2020-04
影响因子：
3.7
通讯作者：
H. Vural;J. Maisch;I. Gerhardt;M. Jetter;S. Portalupi;P. Michler
中科院分区：
文献类型：
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作者：
H. Vural;J. Maisch;I. Gerhardt;M. Jetter;S. Portalupi;P. Michler
固态量子发射器在光子量子技术的发展中起着至关重要的作用。然而，已知有几种去相干机制会影响设备性能和可扩展性。在不同的量子发射体材料中，人们用不同的方法研究了二能级系统的涨落，以捕捉相干约化的演化过程。然而，在按需单光子产生的基本框架中解决光谱扩散的动力学仍然没有解决。因此，挑战在于以高的时间和能量分辨率观察波动对发射光子的性质的直接影响。在这个快速通信中，我们演示了在慢光介质中使用色散将光子频域映射到时域，观察到频率相关的飞行时间。这允许在一个强度相关测量中测量发射光谱和量化光谱扩散动力学。在示例性半导体量子点上，电荷和自旋噪声对光谱扩散的影响被揭示为遵循Ornstein-Uhlenbeck过程。通过单次测量，解决了从激发重复到静止极限的加宽。这使得人们能够提取各种时间尺度的时间相关的双光子干涉能级，这是量子发射器的关键性能度量。
Solid-state quantum emitters are playing a crucial role in the development of photonic quantum technologies. However, several decoherence mechanisms are known to impact the device performances and scalability. In various quantum emitter materials the fluctuation of the two-level system has been investigated by different methods to capture the evolution of coherence reduction. However, resolving the dynamics of spectral diffusion in the fundamental framework of on-demand single-photon generation remained unsolved. Hereby, the challenge is to observe with high time and energy resolution the impact of fluctuations directly in the properties of the emitted photons. In this Rapid Communication, we demonstrate the use of dispersion in a slow-light medium to map the photons frequency domain into time domain, observed as frequency-dependent time-of-flight. This allows for the measurement of the emission spectrum and the quantification of the spectral diffusion dynamics in one intensity correlation measurement. On exemplary semiconductor quantum dots, the impact of charge and spin noise on the spectral diffusion are revealed to follow an Ornstein-Uhlenbeck process. By a single measurement, broadening from the excitation repetition up to the stationary limit is resolved. This enables one to extract time-dependent two-photon interference visibilities for various timescales, which is a key performance measure for quantum emitters.