NAQUAS: Non-equilibrium dynamics in Atomic systems for QUAntum Simulation

物理学各个领域的最新进展表明，我们有能力在定制的系统和材料中控制量子效应，从而为量子技术的光明未来铺平了道路。然而，这种量子装置的出现要求人们理解非平衡统计物理中的基本问题，这可以为完全控制量子系统铺平道路，从而加强新的应用并提供创新的视角。本项目致力于研究和控制跨越相变驱动的量子多体系统的非平衡性质。在几种办法中，它将主要侧重于缓慢淬火，并借鉴Kibble-Zurek(KZ)机制所提供的理解。这一相当简单的范式将均衡与非均衡属性联系在一起，并构成了缩放假说的基准。它可能为解决相关的开放问题铺平道路，这些问题是我们理解非平衡动力学的核心，也是以稳健的方式运行任何量子模拟器的关键问题。从这个动机出发，我们将通过分析KZ动力学的预测来检验它的有效性极限，从而阐明它的预测能力，并将这个范例扩展到具有长程相互作用的量子临界系统和拓扑相变。我们将把凝聚态物理、量子光学、统计物理和量子信息的创新理论思想与超冷原子量子气体的先进实验结合起来。量子气体是一个独特的平台，可以为模型系统提供我们雄心勃勃的目标所需的灵活性和控制水平。它们的清洁性和对退相干的稳健性将极大地加强理论和实验之间的有效相互作用，并提供一个研究平台，其结果预计将对广泛的学科产生强大的科学影响。在短时间内，我们将利用这一知识为量子模拟器开发可行的协议。总体而言，我们预计这一项目的结果将为下一代量子器件和模拟器的开发奠定基础。

Recent progress in various areas of physics has demonstrated our ability to control quantum effects in customized systems and materials, thus paving the way for a promising future for quantum technologies. The emergence of such quantum devices, however, requires one to understand fundamental problems in non-equilibrium statistical physics, which can pave the way towards full control of quantum systems, thus reinforcing new applications and providing innovative perspectives. This project is dedicated to the study and the control of out-of-equilibrium properties of quantum many-body systems which are driven across phase transitions. Among several approaches, it will mainly focus on slow quenches and draw on the understanding delivered by the Kibble-Zurek (KZ) mechanism. This rather simple paradigm connects equilibrium with out-of-equilibrium properties and constitutes a benchmark for scaling hypothesis. It could pave the way towards tackling relevant open questions, which lie at the heart of our understanding of out-of-equilibrium dynamics and are key issues for operating in a robust way any quantum simulator. Starting from this motivation, we will test the limits of validity of the KZ dynamics by analyzing its predictions, thus clarifying its predictive power, and extend this paradigm to quantum critical systems with long-range interactions and to topological phase transitions. We will combine innovative theoretical ideas of condensed-matter physics, quantum optics, statistical physics and quantum information, with advanced experiments with ultracold atomic quantum gases. Quantum gases are a unique platform for providing model systems with the level of flexibility and control necessary for our ambitious goal. Their cleanness and their robustness to decoherence will greatly enhance the efficient interplay between theory and experiments, and provide a platform of studies whose outcomes are expected to have a strong scientific impact over a wide range of disciplines. On the short time scale we will exploit this knowledge to develop viable protocols for quantum simulators. In general, we expect that the results of this project will lay the ground for the development of the next generation of quantum devices and simulators.