标题： 量子绝热和非绝热过程中的弦断裂动力学 显示英文标题

标题： String-Breaking Dynamics in Quantum Adiabatic and Diabatic Processes

摘要： 禁闭禁止通过称为弦断裂的过程在自然界中隔离色荷，例如夸克：两个电荷的分离会导致连接这些电荷的色通量能量增加，可视化为一条弦。最终，产生额外电荷在能量上是被鼓励的，因此会断裂这条弦。这种现象可以在更简单的模型中进行探测，包括量子自旋链，从而增强对弦断裂动力学的理解。一个具有挑战性的任务是理解在非平衡设置下，随着时间推移弦断裂是如何发生的。这项工作建立了由随时间逐渐增加的弦张力引起的动态弦断裂的物理现象。因此，它超越了瞬时淬火过程，并能够在更受控的设置中跟踪弦的实时演化。我们关注量子伊辛链家族中的域墙禁闭。我们的结果表明，对于足够短的弦和缓慢的演化，弦断裂可以通过类似于Landau-Zener过程的两态量子系统的转换动力学来描述。对于更长的弦，会出现更复杂的时空模式：弦通过形成气泡（不同大小的翻转自旋区域）的叠加来断裂，这涉及高度激发的状态。最后，我们证明仅由量子涨落驱动的弦断裂在存在足够长程相互作用的情况下是可以实现的。这项工作对于研究量子模拟实验中的弦断裂具有直接的相关性。 显示英文摘要

摘要： Confinement prohibits isolation of color charges, e.g., quarks, in nature via a process called string breaking: the separation of two charges results in an increase in the energy of a color flux, visualized as a string, connecting those charges. Eventually, creating additional charges is energetically favored, hence breaking the string. Such a phenomenon can be probed in simpler models, including quantum spin chains, enabling enhanced understanding of string-breaking dynamics. A challenging task is to understand how string breaking occurs as time elapses, in an out-of-equilibrium setting. This work establishes the phenomenology of dynamical string breaking induced by a gradual increase of string tension over time. It, thus, goes beyond instantaneous quench processes and enables tracking the real-time evolution of strings in a more controlled setting. We focus on domain-wall confinement in a family of quantum Ising chains. Our results indicate that, for sufficiently short strings and slow evolution, string breaking can be described by the transition dynamics of a two-state quantum system akin to a Landau-Zener process. For longer strings, a more intricate spatiotemporal pattern emerges: the string breaks by forming a superposition of bubbles (domains of flipped spins of varying sizes), which involve highly excited states. We finally demonstrate that string breaking driven only by quantum fluctuations can be realized in the presence of sufficiently long-ranged interactions. This work holds immediate relevance for studying string breaking in quantum-simulation experiments.