Interacting Atoms in an Optical Lattice

该项目涉及一系列在远距离共振光学晶格中与冷原子相互作用的实验。将制备和研究耦合和独立的一维(1D)玻色子气体阵列，以帮助解决量子统计力学和量子相变的一些突出谜团。该小组之前的实验已经在一维空间探索了玻色气体的物理学，证明了这些气体永远不会热化。为了探索一维和三维行为之间的交叉，新的实验将放宽使一维原子气体不热化的条件，并将应用新的工具来测量热化的开始。特别是，将开发一种低能量一维原子对撞机。这些实验将解决一个长期悬而未决的理论问题，即在多体量子系统中存在混沌的阈值，就像经典力学中的那样。这个项目可能会阐明宏观行为的不可逆性是如何由单个原子的可逆行为引起的。此外，还将首次测量一维气体的动量分布，并研究具有可变相互作用的二维气体。这项工作的更广泛影响在于，冷原子实验能够为非线性动力学和数学物理中长期悬而未决的问题提供答案。这些实验将在这一重要的物理技术领域培养本科生、研究生和博士后研究人员。

This project involves a series of experiments with interacting cold atoms in far-off-resonance optical lattices. Arrays of coupled and independent one-dimensional (1D) gases of bosons will be prepared and studied to help resolve some outstanding mysteries of quantum statistical mechanics and quantum phase transitions. Prior experiments by the group have explored the physics of Bose-gases in one dimension, demonstrating that these gases never thermalize. In order to explore the crossover between one-dimensional and three-dimensional behavior, new experiments will relax the conditions that make 1D atomic gases not thermalize, and will apply new tools to measuring the onset of thermalization. In particular, a low energy 1D atom collider will be developed. These experiments will address a long open theoretical question of the existence of a threshold for chaos in a many-body quantum system, as there is in classical mechanics. This project may clarify how irreversibility of macroscopic behavior arises from the reversible behavior of individual atoms. In addition, 1D gas momentum distributions will be measured for the first time, and two-dimensional (2D) gases with variable interactions will be studied. The broader impact of this work lies in the ability of cold-atom experiments to provide answers to long-open questions in nonlinear dynamics and mathematical physics. These experiments will train undergraduate, graduate, and postdoctoral researchers in this technologically-important area of physics.