Quantum emitters in the presence of an electromagnetic reservoir with varying density of states, or structure, can undergo a rich set of dynamical behavior. In particular, the reservoir can be tailored to have a memory of past interactions with emitters, in contrast to memoryless Markovian dynamics of typical open systems. In this article, we investigate the non-Markovian dynamics of a superconducting qubit strongly coupled to a superconducting waveguide engineered to have both a sharp spectral variation in its transmission properties and a slowing of light by a factor of 650. Tuning the qubit into the spectral vicinity of the passband of this slow-light waveguide reservoir, we observe a 400-fold change in the emission rate of the qubit, along with oscillatory energy relaxation of the qubit resulting from the beating of bound and radiative dressed qubit-photon states. Furthermore, upon addition of a reflective boundary to one end of the waveguide, we observe revivals in the qubit population on a timescale 30 times longer than the inverse of the qubit’s emission rate, corresponding to the round-trip travel time of an emitted photon. By in situ tuning of the qubit-waveguide interaction strength, we also probe a crossover between Markovian and non-Markovian qubit emission dynamics in the presence of feedback from waveguide reflections. With this superconducting circuit platform, future studies of multiqubit interactions via highly structured reservoirs and the generation of multiphoton highly entangled states are possible.

中文翻译：

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耦合到结构光子库的人造原子的坍塌和复活

在具有不同状态密度或结构的电磁库存在的情况下，量子发射器可以经历一组丰富的动力学行为。特别是，与典型开放系统的无记忆马尔可夫动力学相反，储层可以被定制为具有过去与发射器相互作用的记忆。在本文中，我们研究了与超导波导强耦合的超导量子位的非马尔可夫动力学，该波导设计为在其传输特性中具有急剧的光谱变化和 650 倍的光速减慢。将量子位调谐到光谱中在这个慢光波导储存器的通带附近，我们观察到量子位发射速率的 400 倍变化，随着束缚和辐射修饰的量子位光子状态的跳动导致量子位的振荡能量弛豫。此外，在波导的一端添加反射边界后，我们观察到量子位群在比量子位发射速率倒数长 30 倍的时间尺度上恢复，对应于发射光子的往返旅行时间。经过在原位调谐量子位-波导相互作用强度的同时，我们还探讨了存在波导反射反馈的马尔可夫量子位发射动力学和非马尔可夫量子位发射动力学之间的交叉。有了这个超导电路平台，未来通过高度结构化的储层和多光子高度纠缠态的产生来研究多量子位相互作用是可能的。