Phase diagram and optimal control for n-tupling discrete time crystal
Phase diagram and optimal control for n-tupling discrete time crystal
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DOI：
10.1088/1367-2630/abb03e
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发表时间：
2020-04
影响因子：
3.3
通讯作者：
Arkadiusz Kuro's;R. Mukherjee;Weronika Golletz;F. Sauvage;Krzysztof Giergiel;F. Mintert;K. Sacha
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作者：
Arkadiusz Kuro's;R. Mukherjee;Weronika Golletz;F. Sauvage;Krzysztof Giergiel;F. Mintert;K. Sacha
在系统中自发地打破时间平移对称性的一个显著结果是时间晶体的出现。在周期性驱动的系统中，可以实现离散时间晶体（DTC），其具有驱动周期的n倍的周期性。然而，所有的实验观察已经进行了倍周期和三倍周期DTC。新的物理学可以通过在时域中模拟多体物理学来产生，这需要真正实现n元组DTC。超冷玻色子原子在振荡镜上的共振碰撞是实现大周期直接转矩控制的模型之一。DTC的制备要求控制超冷玻色子原子的初始分布随镜频的变化沿着。在这项工作中，我们证明了这样的DTC是强大的原子的初始分布的扰动。我们展示了如何贝叶斯方法可以用来加强控制的初始状态的准备，以及有效地计算这样一个模型的相图。此外，我们通过分析量子多体波动来研究DTC的稳定性，并表明它们不会显示加热的特征。
A remarkable consequence of spontaneously breaking the time translational symmetry in a system, is the emergence of time crystals. In periodically driven systems, discrete time crystals (DTC) can be realized which have a periodicity that is n times the driving period. However, all of the experimental observations have been performed for period-doubling and period-tripling DTC. Novel physics can arise by simulating many-body physics in the time domain, which would require a genuine realisation of the n-tupling DTC. A system of ultra-cold bosonic atoms bouncing resonantly on an oscillating mirror is one of the models that can realise large period DTC. The preparation of DTC demands control in creating the initial distribution of the ultra-cold bosonic atoms along with the mirror frequency. In this work, we demonstrate that such DTC is robust against perturbations to the initial distribution of atoms. We show how Bayesian methods can be used to enhance control in the preparation of the initial state as well as to efficiently calculate the phase diagram for such a model. Moreover, we examine the stability of DTCs by analyzing quantum many-body fluctuations and show that they do not reveal signatures of heating.