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arXiv 2305.08400quant-phcond-mat.stat-mech
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量子相干辅助的动力学相变

Quantum coherence assisted dynamical phase transition

Bao-Ming Xu

AI总结:

本文研究一维横场量子 Ising 模型中相干 Gibbs 态的淬火动力学,借助 Fisher 零点、速率函数和绕数揭示量子相可恢复传统 DQPT 并诱发独立于平衡临界点的新相变。

摘要:

量子相干无疑将在理解量子多体系统动力学方面发挥基础性作用,因此揭示其真正贡献具有重要意义。本文将讨论专门聚焦于初始制备在相干 Gibbs 态下的一维横场量子 Ising 模型,并研究量子相干对动力学相变(DQPT)的影响。在对横场强度进行淬火后,我们通过 Fisher 零点、速率函数和绕数来研究量子相干的效应。我们发现,量子相干不仅恢复了与量子相变相关的传统 DQPT,还产生了一些完全新颖的、独立于平衡量子临界点的 DQPT。在这些全新的 DQPT 中,Fisher 零点线与虚轴相交两次,即存在两个临界模式,其中一个使绕数向下跳变,另一个使其向上跳变。我们还发现,速率函数不能用于描述高温下的 DQPT,因为临界模式不再占主导地位。这项工作为量子临界现象与量子相干之间的基本联系提供了新的启示。

英文摘要:

Quantum coherence will undoubtedly play a fundamental role in understanding the dynamics of quantum many-body systems, thereby to reveal its genuine contribution is of great importance. In this paper, we specialize our discussions on the one-dimensional transverse field quantum Ising model initialized in the coherent Gibbs state, and investigate the effects of quantum coherence on dynamical phase transition (DQPT). After quenching the strength of the transverse field, the effects of quantum coherence are studied by Fisher zeros, rate function and winding number. We find that quantum coherence not only recovers the traditional DQPT related to quantum phase transition, but also generates some entirely new DQPTs which are independent of equilibrium quantum critical point. In these entirely new QDPTs, the line of Fisher zeros cuts the imaginary axis twice, i.e., there are two critical modes, one makes the winding number jump down but another makes it jump up. We also find that the rate function can not be used to describe DQPT at high temperature, because the critical mode no longer dominates. This work sheds new light on the fundamental connection between quantum critical phenomena and quantum coherence.

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。

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