Observation of hydrodynamization and local prethermalization in 1D Bose gases
Observation of hydrodynamization and local prethermalization in 1D Bose gases
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DOI：
10.1038/s41586-023-05979-9
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发表时间：
2022-10
期刊：
影响因子：
64.8
通讯作者：
Yuan Le;Yicheng Zhang;S. Gopalakrishnan;M. Rigol;D. Weiss
中科院分区：
文献类型：
--
作者：
Yuan Le;Yicheng Zhang;S. Gopalakrishnan;M. Rigol;D. Weiss
流体动力学精确地描述了相对论重离子碰撞实验之前，当地的热平衡建立。这种出乎意料的流体动力学的快速启动--发生在最快的时间尺度上--被称为流体动力学。当一个相互作用的量子系统被一个比它的基态能量密度大得多的能量密度淬灭时，它就会发生。在水力发电过程中，能量在不同的能量尺度上重新分配。流体动力学先于动量模之间的局部平衡，这是一个广义吉布斯系综的局部预热化，在近可积系统或局部热化在不可积系统。虽然许多量子动力学理论都假设了局域预热化，但相关的时间尺度还没有被实验研究。在这里，我们使用一维玻色气体阵列直接观察流体动力学和局部预热化。在我们施加布拉格散射脉冲后，流体动力学在远距离动量模式之间的能量快速重新分配中是明显的，这发生在与布拉格峰值能量相关的时间尺度上。局部预热化可以在附近动量模之间占据的缓慢再分配中看到。我们发现，在我们的系统中的局部预热化的时间尺度是成反比的动量。在流体动力学和局部预热化过程中，现有的理论不能定量地模拟我们的实验。在Tonks-Girardeau极限中的精确理论计算显示出定性上相似的特征。
Hydrodynamics accurately describe relativistic heavy-ion collision experiments well before local thermal equilibrium is established. This unexpectedly rapid onset of hydrodynamics—which takes place on the fastest available timescale—is called hydrodynamization, –. It occurs when an interacting quantum system is quenched with an energy density that is much greater than its ground-state energy density,. During hydrodynamization, energy gets redistributed across very different energy scales. Hydrodynamization precedes local equilibration among momentum modes, which is local prethermalization to a generalized Gibbs ensemble,in nearly integrable systems or local thermalization in non-integrable systems. Although many theories of quantum dynamics postulate local prethermalization,, the associated timescale has not been studied experimentally. Here we use an array of one-dimensional Bose gases to directly observe both hydrodynamization and local prethermalization. After we apply a Bragg scattering pulse, hydrodynamization is evident in the fast redistribution of energy among distant momentum modes, which occurs on timescales associated with the Bragg peak energies. Local prethermalization can be seen in the slower redistribution of occupation among nearby momentum modes. We find that the timescale for local prethermalization in our system is inversely proportional to the momenta involved. During hydrodynamization and local prethermalization, existing theories cannot quantitatively model our experiment. Exact theoretical calculations in the Tonks–Girardeau limit show qualitatively similar features.