发表机构
Università di Napoli Federico II; SPIN-CNR; INFN, Sezione di Napoli（那不勒斯费德里科二世大学; SPIN-国家研究委员会; 意大利国家核物理研究所那不勒斯分部）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过矩阵乘积态数值模拟，在受周期驱动的强无序海森堡自旋链中发现离散时间晶体行为，揭示了旋转角误差下的中间动力学 regime 及弱关联动力学特征。
AI 中文摘要
离散时间晶体是物质的一种非平衡相，其特征是离散时间平移对称性的自发破缺。我们基于矩阵乘积态方法开展大量数值模拟，在受周期驱动的强无序海森堡相互作用自旋链（包括各向同性点）中，提供了离散时间晶体行为的证据。从多体局域 regime 出发，我们观察到由δ脉冲诱导的旋转，会在自旋可观测量中产生显著的半驱动频率次谐波响应。我们通过纠缠熵、量子费舍尔信息、短程自旋关联和受限控制ergotropy，研究该响应对旋转角误差的稳定性。增大旋转误差会揭示出一个介于时间晶体响应和Floquet局域响应之间的中间动力学 regime，在此 regime 中，多数可观测量表现出弱关联动力学的特征，让人联想到安德森局域化。
英文摘要
A discrete time crystal is an out-of-equilibrium phase of matter characterized by the spontaneous breaking of discrete time-translation symmetry. Using extensive numerical simulations based on matrix-product-state methods, we provide evidence for discrete time-crystalline behavior in strongly disordered spin chains with Heisenberg interactions, including the isotropic point, subject to periodic driving. Starting from a many-body localized regime, we observe that rotations induced by delta kicks produce a pronounced subharmonic response at half the drive frequency in spin observables. We investigate the stability of this response against rotation-angle errors through entanglement entropy, quantum Fisher information, short-range spin correlations, and restricted-control ergotropy. Increasing the rotation error reveals an intermediate dynamical regime separating the time-crystalline and Floquet-localized responses. In this regime, most observables exhibit signatures of weakly correlated dynamics reminiscent of Anderson localization.
Comments22 pages, 11 figures (25 images)
