论文标题
初始条件和非平衡量子动力学的普遍性的空间
Space of initial conditions and universality in nonequilibrium quantum dynamics
论文作者
论文摘要
我们通过分析研究了初始条件在自发损坏的对称性方面的一维铁磁体中，初始条件在非平衡量子动力学中的作用。我们分析了本地操作员对域壁类型初始条件的无限维空间的期望值，通常是在两个不同基态之间在空间上插值的初始条件。在很大程度上，单一时间演化发生在最初条件的空间不均匀性产生的光锥内。在光锥的最终部分中，时空依赖的形式是通用的，因为它是由平衡通用类别的数据指定的。变量$ x/t $中的全局极限形状随初始条件而变化。在具有两个以上基础状态的系统中，相互作用参数的调整可以诱导过渡，该转变是在平衡处的经典系统中发生的界面润湿跃迁的非平衡量子类似物。我们通过Ising，Potts和Ashkin-Teller链的示例来说明总体结果。
We study analytically the role of initial conditions in nonequilibrium quantum dynamics considering the one-dimensional ferromagnets in the regime of spontaneously broken symmetry. We analyze the expectation value of local operators for the infinite-dimensional space of initial conditions of domain wall type, generally intended as initial conditions spatially interpolating between two different ground states. At large times the unitary time evolution takes place inside a light cone produced by the spatial inhomogeneity of the initial condition. In the innermost part of the light cone the form of the space-time dependence is universal, in the sense that it is specified by data of the equilibrium universality class. The global limit shape in the variable $x/t$ changes with the initial condition. In systems with more than two ground states the tuning of an interaction parameter can induce a transition which is the nonequilibrium quantum analog of the interfacial wetting transition occurring in classical systems at equilibrium. We illustrate the general results through the examples of the Ising, Potts and Ashkin-Teller chains.
