Discrete (DTCs) and continuous time crystals (CTCs) are novel dynamical many-body states, that are characterized by robust self-sustained oscillations, emerging via spontaneous breaking of discrete or continuous time translation symmetry. DTCs are periodically driven systems that oscillate with a subharmonic of the external drive, while CTCs are continuously driven and oscillate with a frequency intrinsic to the system. Here, we explore a phase transition from a continuous time crystal to a discrete time crystal. A CTC with a characteristic oscillation frequency ωCTC is prepared in a continuously pumped atom-cavity system. Modulating the pump intensity of the CTC with a frequency ωdr close to 2ωCTC leads to robust locking of ωCTC to ωdr/2 , and hence a DTC arises. This phase transition in a quantum many-body system is related to subharmonic injection locking of non-linear mechanical and electronic oscillators or lasers.

中文翻译：

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观察从连续时间晶体到离散时间晶体的相变


离散 (DTC) 和连续时间晶体 (CTC) 是新颖的动态多体态，其特征是鲁棒的自持振荡，通过离散或连续时间平移对称性的自发破缺而出现。 DTC 是周期性驱动的系统，以外部驱动的分谐波振荡，而 CTC 则以系统固有的频率连续驱动和振荡。在这里，我们探索从连续时间晶体到离散时间晶体的相变。具有特征振荡频率的 CTC ω CTC是在连续泵浦原子腔系统中制备的。 用频率调节 CTC 的泵浦强度ω博士附近2 ω CTC导致稳健的锁定ω CTC到ω博士/ 2 ，因此出现 DTC。量子多体系统中的这种相变与非线性机械和电子振荡器或激光器的分谐波注入锁定有关。