Smith A, Knolle J, Moessner R, Kovrizhin D L
T.C.M. group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany.
Phys Rev Lett. 2017 Oct 27;119(17):176601. doi: 10.1103/PhysRevLett.119.176601. Epub 2017 Oct 25.
We study the time evolution after a quantum quench in a family of models whose degrees of freedom are fermions coupled to spins, where quenched disorder appears neither in the Hamiltonian parameters nor in the initial state. Focusing on the behavior of entanglement, both spatial and between subsystems, we show that the model supports a state exhibiting combined area and volume-law entanglement, being characteristic of the quantum disentangled liquid. This behavior appears for one set of variables, which is related via a duality mapping to another set, where this structure is absent. Upon adding density interactions between the fermions, we identify an exact mapping to an XXZ spin chain in a random binary magnetic field, thereby establishing the existence of many-body localization with its logarithmic entanglement growth in a fully disorder-free system.
我们研究了一类模型中量子猝灭后的时间演化，这类模型的自由度是与自旋耦合的费米子，其中猝灭无序既不出现在哈密顿量参数中，也不出现在初始状态中。聚焦于纠缠行为，包括空间纠缠和子系统间的纠缠，我们表明该模型支持一种展现出面积律和体积律纠缠组合的状态，这是量子解纠缠液体的特征。这种行为出现在一组变量中，这组变量通过对偶映射与另一组变量相关，而在另一组变量中不存在这种结构。在费米子之间加入密度相互作用后，我们确定了与随机二元磁场中的XXZ自旋链的精确映射，从而在一个完全无无序的系统中建立了具有对数纠缠增长的多体局域化的存在性。
