Rademaker Louk, Abanin Dmitry A
Department of Theoretical Physics, University of Geneva, 1211 Geneva, Switzerland.
Phys Rev Lett. 2020 Dec 31;125(26):260405. doi: 10.1103/PhysRevLett.125.260405.
Spin glasses and many-body localization (MBL) are prime examples of ergodicity breaking, yet their physical origin is quite different: the former phase arises due to rugged classical energy landscape, while the latter is a quantum-interference effect. Here, we study quantum dynamics of an isolated 1D spin glass under application of a transverse field. At high energy densities, the system is ergodic, relaxing via a resonance avalanche mechanism, that is also responsible for the destruction of MBL in nonglassy systems with power-law interactions. At low energy densities, the interaction-induced fields obtain a power-law soft gap, making the resonance avalanche mechanism inefficient. This leads to the persistence of the spin-glass order, as demonstrated by resonance analysis and by numerical studies. A small fraction of resonant spins forms a thermalizing system with long-range entanglement, making this regime distinct from the conventional MBL. The model considered can be realized in systems of trapped ions, opening the door to investigating slow quantum dynamics induced by glassiness.
自旋玻璃和多体局域化（MBL）是遍历性破缺的典型例子，但其物理起源却大不相同：前者的相是由于崎岖的经典能量景观产生的，而后者是一种量子干涉效应。在此，我们研究了在横向场作用下孤立一维自旋玻璃的量子动力学。在高能量密度下，系统是遍历性的，通过共振雪崩机制弛豫，该机制也导致了具有幂律相互作用的非玻璃态系统中MBL的破坏。在低能量密度下，相互作用诱导场获得幂律软能隙，使共振雪崩机制效率低下。这导致了自旋玻璃序的持续存在，这一点通过共振分析和数值研究得到了证明。一小部分共振自旋形成了一个具有长程纠缠的热化系统，使得这个区域有别于传统的MBL。所考虑的模型可以在捕获离子系统中实现，为研究由玻璃态诱导的缓慢量子动力学打开了大门。
