%0 Journal Article %J Phys. Rev. Lett. %D 2020 %T Many-Body Dephasing in a Trapped-Ion Quantum Simulator %A Harvey B. Kaplan %A Lingzhen Guo %A Wen Lin Tan %A Arinjoy De %A Florian Marquardt %A Guido Pagano %A Christopher Monroe %X

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 work, we observe and analyse 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 and observe the experimental evidence for the theoretically predicted regime of many-body dephasing. 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 even for the long-time non-integrable dynamics. We find that the measured fluctuations are exponentially suppressed with increasing system size, consistent with theoretical predictions. 

%B Phys. Rev. Lett. %V 125 %8 8/24/2020 %G eng %U https://arxiv.org/abs/2001.02477 %N 120605 %R https://doi.org/10.1103/PhysRevLett.125.120605