用Loschiral累积量确定强关联多体系统的动态量子相变
Determination of dynamical quantum phase transitions in strongly correlated many-body systems using Loschmidt cumulants
摘要：
动态相变将临界性的概念扩展到非稳态设置，并且以时间演化量子系统的宏观性质的突然变化为特征。动力学相变的研究结合了对称性、拓扑学和非平衡物理学的各个方面，然而，预测大的相互作用的量子系统的时间演化的臭名昭著的困难阻碍了进展。在这里，我们解决这个突出的问题，确定相互作用的多体系统的临界时间淬火后，使用Loschirst累积量。具体地说，我们调查的动力学拓扑相变在相互作用的Kitaev链和自旋1海森堡链。为此，我们绘制出的热力学线的复杂的时间，在那里的Loschitron振幅消失，并确定与虚轴，产生真正的临界时间淬火后的交叉点。对于Kitaev链，我们可以准确地预测临界行为是如何受到强相互作用的影响，这逐渐改变了动态相变发生的时间。我们还讨论了通过测量初始态的能量涨落来预测量子多体系统的第一临界时间的实验前景，并描述了在具有有限数量量子比特的近期量子计算机上实现我们的方法的前景。我们的工作表明，Loscherk累积量是一个强大的工具来解开远离平衡态的强关联多体系统的动力学，我们的方法可以立即应用于更高的维度。
英文摘要：
Dynamical phase transitions extend the notion of criticality to non-stationary settings and are characterized by sudden changes in the macroscopic properties of time-evolving quantum systems. Investigations of dynamical phase transitions combine aspects of symmetry, topology, and non-equilibrium physics, however, progress has been hindered by the notorious difficulties of predicting the time evolution of large, interacting quantum systems. Here, we tackle this outstanding problem by determining the critical times of interacting many-body systems after a quench using Loschmidt cumulants. Specifically, we investigate dynamical topological phase transitions in the interacting Kitaev chain and in the spin-1 Heisenberg chain. To this end, we map out the thermodynamic lines of complex times, where the Loschmidt amplitude vanishes, and identify the intersections with the imaginary axis, which yield the real critical times after a quench. For the Kitaev chain, we can accurately predict how the critical behavior is affected by strong interactions, which gradually shift the time at which a dynamical phase transition occurs. We also discuss the experimental perspectives of predicting the first critical time of a quantum many-body system by measuring the energy fluctuations in the initial state, and we describe the prospects of implementing our method on a near-term quantum computer with a limited number of qubits. Our work demonstrates that Loschmidt cumulants are a powerful tool to unravel the far-from-equilibrium dynamics of strongly correlated many-body systems, and our approach can immediately be applied in higher dimensions.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
