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arXiv 2409.07481cond-mat.stat-mechcond-mat.softnlin.PS
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非互易Ising模型中的动力学相变

Dynamical phase transitions in the nonreciprocal Ising model

Yael Avni, Michel Fruchart, David Martin, Daniel Seara, Vincenzo Vitelli

AI总结:

该研究通过非互易Ising模型揭示了从静态到时间依赖状态的动力学相变,发现三维中交换相稳定且具时间晶体特性,无序-交换转变属三维XY普适类,并阐明液滴机制对静态有序稳定性的影响。

摘要:

多体系统中的非互易相互作用会导致时间依赖状态,这在生物、化学和生态系统中普遍存在。这些状态在热力学极限下的稳定性以及从静态到时间依赖状态的相变临界行为尚未被完全理解。为解决这些问题,我们研究了一个具有非互易相互作用的极简系统:一个具有两个目标相反的自旋种类的Ising模型。平均场方程预测了三个稳定相:无序相、静态有序相和时间依赖的交换相。大规模数值模拟支持以下结论:(i) 在二维中,交换相被缺陷所破坏;(ii) 在三维中,交换相是稳定的,并具有时间晶体的性质;(iii) 三维中从无序到交换相的转变以三维XY模型的临界指数为特征,对应于连续对称性——时间平移不变性的破缺;(iv) 当两个种类具有完全反对称耦合时,由于液滴增长,静态有序相在任何有限维度中都是不稳定的;(v) 在非对称耦合的一般情况下,通过液滴捕获机制可以恢复静态有序,该机制阻止液滴无限增长。我们提供了完整相图的细节,其中包括一级和二级相变,并研究了系统如何粗化进入交换相和静态有序态。

英文摘要:

Nonreciprocal interactions in many-body systems lead to time-dependent states, commonly observed in biological, chemical, and ecological systems. The stability of these states in the thermodynamic limit and the critical behavior of the phase transition from static to time-dependent states are not yet fully understood. To address these questions, we study a minimalistic system endowed with nonreciprocal interactions: an Ising model with two spin species having opposing goals. The mean-field equation predicts three stable phases: disorder, static order, and a time-dependent swap phase. Large scale numerical simulations support the following: (i) in 2D, the swap phase is destabilized by defects; (ii) in 3D, the swap phase is stable, and has the properties of a time crystal; (iii) the transition from disorder to swap in 3D is characterized by the critical exponents of the 3D XY model, and corresponds to the breaking of a continuous symmetry, time translation invariance; (iv) when the two species have fully anti-symmetric couplings, the static-order phase is unstable in any finite dimension due to droplet growth; (v) in the general case of asymmetric couplings, static order can be restored by a droplet-capture mechanism preventing the droplets from growing indefinitely. We provide details on the full phase diagram which includes first- and second-order-like phase transitions and study how the system coarsens into swap and static-order states.

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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