CAREER: Non-Equilibrium Coherent Many-Body Dynamics with Cold Atoms

在这个项目中，由于冷原子和冷分子系统的独特性质，人们正在探索这些系统中的非平衡动力学。目标是(I)更好地了解强相互作用系统中的非平衡动力学，以及(Ii)使用非平衡动力学作为基准，以表征量子模拟器在哪里可以用来探索经典模拟所不可能的物理。在项目的第一部分，我们正在研究(A)输运动力学的范例，包括通过将系统耦合到储气库气体或空腔模式来设计和测量电流，以及在系统中设计的激发的纯相干传播；以及(B)存在偶极相互作用时的动力学，其动机是关于极性分子的最新实验发展，包括相变过程的时间依赖性和激发的热化。在每种情况下，使用分析技术和数值方法的组合来探索动力学，包括一维系统的含时密度矩阵重正化群方法。这些方法的扩展也将被研究到处理具有远程相互作用的动力学。在项目的第二部分，我们探索在实验中测量纠缠熵的可能性，并利用这些测量来更深入地了解这些系统中的多体动力学。了解微观多粒子系统的非平衡动力学对于描述自然界中发生的非常基本的现象至关重要，包括粒子气体如何达到热平衡，以及固体中运动的传导电子在量子输运过程中的行为。原子和分子的超冷气体实验的最新进展使得在高度可控的系统中探索这种非平衡动力学成为可能，这种非平衡动力学可以通过激光领域中众所周知的过程来操纵和测量。在这个项目的研究部分，我们调查了这些系统的独特性质如何可以用来洞察非平衡动力学的基本方面，包括传输过程和热化。我们将通过我们的计算来寻求对这些过程的更深入的理解，并为未来潜在的实验中探索这些现象设定路线图。我们还将研究在这些实验中测量量子力学纠缠的方法，这既可以用来进一步了解动力学，也可以用来演示量子力学实验实现的动力学超出了最先进的数值方法所能计算的范围。支持的工作的更广泛影响也将通过该项目的教育部分得到加强，我们将举办一系列研讨会，根据当前技术和该项目的研究中的说明性例子向高中教师解释量子力学的基本概念。我们将与老师一起探索可能性，并开发工具来向高中生传达现代物理研究中的基本概念。

In this project, non-equilibrium dynamics in systems of cold atoms and molecules is being explored, as motivated by the unique properties of those systems. The goals are (i) to obtain a better understanding of non-equilibrium dynamics in strongly interacting systems, and (ii) to use non-equilibrium dynamics as a benchmark for characterizing where quantum simulators can be used to explore physics beyond what is possible with classical simulations. In the first part of the project we are studying (a) paradigms of transport dynamics, including the engineering and measurement of currents by coupling the system to a reservoir gas or a cavity mode, as well as purely coherent propagation of excitations engineered in the system; and (b) dynamics in the presence of dipolar interactions, as motivated by recent experimental developments with polar molecules, including the time-dependence of phase transition processes and thermalization of excitations. In each case, the dynamics are bein explored using a combination of analytical techniques and numerical methods, including time-dependent Density Matrix Renormalisation Group methods for 1D systems. Extensions of these methods to the treatment of dynamics with long range interactions will also be investigated. In the second part of the project, we explore possibilities to measure entanglement entropies in experiments, and use these measurements to gain a deeper understanding of many-body dynamics in these systems.Understanding the non-equilibrium dynamics of microscopic many-particle systems is crucial to the description of very fundamental phenomena occurring in nature, including how a gas of particles reaches thermal equilibrium, and how moving conduction electrons in solids behave in quantum transport processes. Recent developments in experiments with ultracold gases of atoms and molecules have made it possible to explore such non-equilibrium dynamics in highly controllable systems, which can be manipulated and measured by well-understood processes in laser fields. In the research part of this project, we investigate how the unique properties of these systems, which are now available in the laboratory can be used to gain insight into fundamental aspects of non-equilibrium dynamics, including transport processes and thermalization. We will look to gain a deeper understanding of these process through our calculations, and to set a roadmap for the exploration of these phenomena in potential future experiments. We will also investigate means to measure the quantum mechanical entanglement in these experiments, which could be used both to gain further insight into the dynamics, and to demonstrate regimes where a quantum mechanical experiment realizes dynamics that go beyond what is computable with state-of-the-art numerical methods. The broader impacts of the supported work will also be enhanced by the education part of this project, where we will run a series of workshops in which basic concepts in quantum mechanics are explained to high-school teachers based on illustrative examples from current technologies, as well as from the research in this project. With the teachers we will explore possibilities and develop tools to communicate basic concepts in modern physics research to high school students.