论文标题
高阶时间晶体相的分形性质
Fractal nature of high-order time crystal phases
论文作者
论文摘要
离散的Floquet时间晶体（DFTC）的特征是自发破坏了Floquet驱动系统的离散时间转换不变性特征。与平衡关键点相比，时间晶状体相位也显示出不同顺序的关键行为，即，振荡的周期为floquet驾驶期的多个$ p> 2 $。在这里，我们介绍了一个新的，实验性的订单参数，无论$ p $的值如何，它都能明确检测结晶阶段，同时也是混乱诊断的有用工具。这种新的范式使我们能够研究远程（LR）的相图（LR）将模型踢到前所未有的深度，从而揭示了具有自相似分形边界的丰富景观。我们的理论图片描述了DFTCS阶段的出现是Floquet驱动器的强度和周期的函数，从而捕获了Floquet-Bloch波中的出现$ \ Mathbb {Z} _p $对称性。
Discrete Floquet time crystals (DFTC) are characterized by the spontaneous breaking of the discrete time-translational invariance characteristic of Floquet driven systems. In analogy with equilibrium critical points, also time-crystalline phases display critical behaviour of different order, i.e., oscillations whose period is a multiple $p > 2$ of the Floquet driving period. Here, we introduce a new, experimentally-accessible, order parameter which is able to unambiguously detect crystalline phases regardless of the value of $p$ and, at the same time, is a useful tool for chaos diagnostic. This new paradigm allows us to investigate the phase diagram of the long-range (LR) kicked Ising model to an unprecedented depth, unveiling a rich landscape characterized by self-similar fractal boundaries. Our theoretical picture describes the emergence of DFTCs phase both as a function of the strength and period of the Floquet drive, capturing the emergent $\mathbb{Z}_p$ symmetry in the Floquet-Bloch waves.
