权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Many-body quantum engines

多体量子引擎

基本信息

批准号：
EP/S02994X/1
负责人：
Gabriele De Chiara
金额：
$ 44万
依托单位：
Queen's University Belfast
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2019
资助国家：
英国
起止时间：
2019 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FS02994X%2F1
关键词：
Many body quantum engines

项目摘要

Thermodynamics, the science of energy transformation, of heat and work, has always played an important and special role in physics. Its formulation in the 19th century was triggered by practical questions of energy balance and efficiency during the industrial revolution. Since then, the laws of thermodynamics have survived every subsequent scientific revolution of the 20th century, including quantum theory and relativity. A surprising connection to information theory came with Maxwell's daemon, a being imagined to be capable of making hot particles move from a cold to a hot thermostat, thus contrary to the normal hot-to-cold heat flow. The information-physics connection was made stronger in the 20th century by the works of Szilard and Landauer, who designed engines powered by information, and Bennett who exorcised the Maxwell's daemon paradox.As the physical dimension of engines get smaller and smaller, strong thermal fluctuations affect the amount of work produced and a new stochastic thermodynamics has been developed in response. Heat, work and entropy are not just functionals of a thermodynamic process anymore, but, because of random fluctuations, they become stochastic variables. The fundamental laws of thermodynamics are recovered when looking at average values. Thanks to the tremendous advance in the experimental realisations of quantum technologies applications of thermodynamics with quantum devices are foreseeable in the near future. In the new emerging field of quantum thermodynamics a considerable effort is being devoted to the design and analysis of thermal machines and refrigerators operating at the quantum level and the theoretical foundation of thermodynamics from quantum principles, including the definition of thermodynamic quantities like heat and work, with inputs from quantum information theory. There are currently several attempts at realising quantum machines, capable of producing work, with a few degrees of freedom, e.g. a single particle. Although quantum thermodynamics is developing very fast, it is not yet clear how to scale up such machines to systems composed of many quantum particles. This achievement would enable practical applications of quantum machines as autonomous devices capable of correcting errors and imperfections in quantum simulators and quantum computers as well as serving as assemblers of quantum materials at the nanoscale.The overarching challenge of this project is to theoretically design thermal machines, that use as working substance an ensemble of many interacting quantum particles. More specifically, we will consider a network of interacting quantum particles, quantum harmonic oscillators and localised spins, externally driven and coupled to thermal and non-equilibrium reservoirs. The network will be arranged in order to transform heat into mechanical work, thus operating as a thermal engine, or to employ external work to extract heat from a cold reservoir for the realisation of a refrigerator. As a further step, we will optimise the geometry and architecture of the network itself to deliver work and refrigeration with the largest power and efficiency. Since it would be a formidable task to optimise all the tens of parameters of the Hamiltonian, we will employ machine learning techniques to this end. Finally, an important fraction of the project will be done in collaboration with two experimental groups working on ultracold atoms with the aim of designing thermal machines that can be realised with their current experimental setups. In collaboration with the J. Sherson (Aarhus) we will design an engine whose working substance and reservoirs are realised with ultracold atoms in optical lattice potentials. In collaboration with T. Donner (Zürich) we will design a refrigerator made of two atomic Bose-Einstein condensates that interact with the common mode of an optical cavity.

热力学是一门研究能量转换、热和功的科学，在物理学中一直起着重要而特殊的作用。它在世纪的形成是由工业革命期间能源平衡和效率的实际问题引发的。从那时起，热力学定律在随后的世纪的每一次科学革命中幸存下来，包括量子理论和相对论。麦克斯韦的守护进程与信息论有着惊人的联系，它被想象成能够使热粒子从一个冷的恒温器移动到一个热的恒温器，从而与正常的从热到冷的热流相反。在世纪，Szilard和Landauer设计了以信息为动力的发动机，班尼特消除了麦克斯韦的守护进程悖论。随着发动机的物理尺寸越来越小，强烈的热涨落影响了产生的功的量，一种新的随机热力学被发展出来。热、功和熵不再仅仅是热力学过程的泛函，但是，由于随机涨落，它们变成了随机变量。当观察平均值时，热力学的基本定律就恢复了。由于量子技术在实验实现方面的巨大进步，可以预见在不久的将来量子器件的热力学应用。在新兴的量子热力学领域，大量的工作致力于设计和分析在量子水平上运行的热机和制冷机，以及量子原理的热力学理论基础，包括热和功等热力学量的定义，以及量子信息理论的输入。目前有几种实现量子机器的尝试，能够产生工作，具有几个自由度，例如单个粒子。虽然量子热力学发展非常快，但目前还不清楚如何将这种机器扩展到由许多量子粒子组成的系统。这一成就将使量子机器作为能够校正量子模拟器和量子计算机中的错误和缺陷的自主设备以及作为纳米级量子材料组装器的实际应用成为可能。该项目的首要挑战是从理论上设计热机器，该机器使用许多相互作用的量子粒子的系综作为工作物质。更具体地说，我们将考虑相互作用的量子粒子，量子谐振子和局域自旋，外部驱动和耦合到热和非平衡水库的网络。该网络将被布置为将热量转换为机械功，从而作为热力发动机运行，或者使用外部功从冷储库提取热量以实现制冷机。下一步，我们将优化网络本身的几何结构和架构，以最大的功率和效率提供工作和制冷。由于优化哈密尔顿算子的所有数十个参数将是一项艰巨的任务，因此我们将采用机器学习技术来实现这一目标。最后，该项目的一个重要部分将与两个研究超冷原子的实验小组合作完成，目的是设计可以用他们目前的实验装置实现的热机。在与J. Sherson（Aarhus）的合作中，我们将设计一种发动机，其工作物质和水库都是用光学晶格势中的超冷原子实现的。与T. Donner（苏黎世），我们将设计一个由两个原子玻色-爱因斯坦凝聚体制成的冰箱，它们与光学腔的共模相互作用。