Kaplan Harvey B, Guo Lingzhen, Tan Wen Lin, De Arinjoy, Marquardt Florian, Pagano Guido, Monroe Christopher
Joint Quantum Institute, Department of Physics and Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA.
Max Planck Institute for the Science of Light, Staudtstrasse 2, 91058 Erlangen, Germany.
Phys Rev Lett. 2020 Sep 18;125(12):120605. doi: 10.1103/PhysRevLett.125.120605.
How a closed interacting quantum many-body system relaxes and dephases as a function of time is a fundamental question in thermodynamic and statistical physics. In this Letter, we analyze and observe the persistent temporal fluctuations after a quantum quench of a tunable long-range interacting transverse-field Ising Hamiltonian realized with a trapped-ion quantum simulator. We measure the temporal fluctuations in the average magnetization of a finite-size system of spin-1/2 particles. We experiment in a regime where the properties of the system are closely related to the integrable Hamiltonian with global spin-spin coupling, which enables analytical predictions for the long-time nonintegrable dynamics. The analytical expression for the temporal fluctuations predicts the exponential suppression of temporal fluctuations with increasing system size. Our measurement data is consistent with our theory predicting the regime of many-body dephasing.
一个封闭的相互作用量子多体系统如何随时间弛豫和退相是热力学和统计物理学中的一个基本问题。在本信函中，我们分析并观测了利用囚禁离子量子模拟器实现的可调谐长程相互作用横向场伊辛哈密顿量量子猝灭后的持续时间涨落。我们测量了自旋为1/2粒子的有限尺寸系统平均磁化强度的时间涨落。我们在一个系统性质与具有全局自旋 - 自旋耦合的可积哈密顿量密切相关的区域进行实验，这使得能够对长时间的不可积动力学进行解析预测。时间涨落的解析表达式预测了随着系统尺寸增加时间涨落的指数抑制。我们的测量数据与我们预测多体退相区域的理论一致。
