Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA.
Science. 2021 Jan 15;371(6526):296-300. doi: 10.1126/science.abb4928.
Long-lived excited states of interacting quantum systems that retain quantum correlations and evade thermalization are of great fundamental interest. We create nonthermal states in a bosonic one-dimensional (1D) quantum gas of dysprosium by stabilizing a super-Tonks-Girardeau gas against collapse and thermalization with repulsive long-range dipolar interactions. Stiffness and energy-per-particle measurements show that the system is dynamically stable regardless of contact interaction strength. This enables us to cycle contact interactions from weakly to strongly repulsive, then strongly attractive, and finally weakly attractive. We show that this cycle is an energy-space topological pump (caused by a quantum holonomy). Iterating this cycle offers an unexplored topological pumping method to create a hierarchy of increasingly excited prethermal states.
相互作用的量子系统的长寿命激发态保留了量子相关性并避免热化，这具有重要的基础意义。我们通过稳定排斥长程偶极相互作用来防止钕玻色子一维（1D）量子气体的坍缩和热化，从而在其中产生非热态。僵硬度和能量-粒子测量表明，无论接触相互作用强度如何，系统都是动态稳定的。这使我们能够将接触相互作用从弱到强排斥，再到强吸引，最后到弱吸引循环。我们表明，这个循环是能量空间拓扑泵（由量子霍尔效应引起）。迭代这个循环为创建越来越激发的预热态层次结构提供了一种探索中的拓扑泵送方法。
