Towards the study of quantum engines in 41K-87Rb Bose-Bose Mixtures

这个项目旨在解决的具体问题可以概括为以下四点：1。理解单个粒子的热化与浴-热化和平衡通常按照两种不同的方法处理，一种来自量子光学，另一种来自量子信息理论。这一目标的核心是对这些基本现象提供（目前缺乏的）统一的理解。实现简单的量子热机-实现量子引擎需要实现量子热力学变换，并将它们组合在可以重复运行的循环中。我们的实验将能够实现量子卡诺，奥托和柴油机。3.工作介质的量子工程--量子态比经典态更“丰富”。它们的特点是量子相干性，人们可以从中提取功。功也可以从量子相关性中提取。4.探索原型多粒子量子引擎-多体效应也可以用来建造更高效的引擎。一种由相互作用的量子粒子组成的工作流体已经被证明可以产生比单粒子发动机总和更多的功率。将使用超冷原子混合物，以实现所需的低温和对系统的控制程度。特别是，这个实验选择的原子种类是41 K，这将是我们的单原子量子引擎，87 Rb，它将作为一个热浴。这两种碱金属可以通过激光冷却和后蒸发冷却冷却到超冷状态。此外，这两个物种提出了一个非常方便的种间Feshbach共振，使我们能够调整它们之间的相互作用。在目前的状态下，我们能够达到87 Rb的超冷区和41 K的近超冷区。在此之后，我们将不得不在新的方法来操纵原子，总结在以下几点：1。光纤-原子接口和基于光纤的技术-与光纤集成的量子系统提供了前所未有的灵活性和重新配置的机会。大量的量子实验已经追求这样的方向，以将量子系统与微制造的纤维（包括原子、机械谐振器、离子、碳纳米管、量子点以及金刚石中的威尔斯和NV中心）进行接口。这种多功能性正在推动基于纤维的系统成为非常令人兴奋的技术平台。实现单原子操作的光镊--这是目前超冷原子领域的热门课题之一。该技术有望实现任意原子阵列，并且在理解少体物理和构建量子传感器件方面也被证明非常有效。其中最具挑战性的，但诱人的方向是实现不同种类的原子的光镊。这将展示第一个物种选择性光学镊子，从而有助于这一令人兴奋的探索。

The particular questions this project aims to address can be summarised in the following four points: 1. Understanding the thermalization of the single particle with a bath - Thermalization and equilibration are usually treated following two different approaches, one originating from quantum optics and the other from quantum information theory. The provision of a (currently lacking) unified understanding of such fundamental phenomena is the core of this objective.2. Realisation of simple quantum thermo-machines - Realizing quantum engines requires to realize quantum thermodynamic transformations and combine them in cycles that can be run repeatedly. Our experiment will be able to realize Quantum Carnot, Otto and Diesel engines. 3. Quantum engineering of working medium - Quantum states are "richer" than classical ones. They feature quantum coherences from which one can extract work. Work can also be extracted from quantum correlations.4. Exploration of prototype many-particle quantum engines - Many-body effects can also be exploited to build more efficient engines. A working fluid of interacting quantum particles has been proven to produce more power than the sum of single-particle engines. Ultra cold atoms mixtures will be used in order to achieve the required low temperatures and degree of control over the system. In particular, the chosen atomic species for this experiment are 41K, which will be our single atom quantum engine, and 87Rb, which will act as a thermal bath. These two alkali metal can be cooled via laser cooling and a posterior evaporative cooling to the ultra cold regime. Furthermore, these two species present a very convenient interspecies Feshbach resonance that allows us to tune the interaction between them. In the current state, we are able to reach the ultra cold regime of 87Rb and the near ultra cold regime of 41K. After this, we will have to work in the novel methods to manipulate the atoms which are summarised in the following points: 1. Fibre-atom interfaces and fibre-based technology - Quantum systems integrated with optical fibres offer unprecedented flexibility and reconfiguration opportunities. A large number of quantum experiments have pursued such direction to interface quantum systems with micro-fabricated fibres, including atoms, mechanical resonators, ions, carbon nanotubes, quantum dots and wells and NV-centres in diamonds. Such versatility is promoting fibre-based systems as very exciting technological platforms.2. Realizing optical tweezers for single-atom manipulations - This is currently one of the hottest topics in the area of ultra-cold atoms. This technique is promising to realize arbitrary atom arrays atom by atom, and has also proven to be very effective in understanding few body physics and building quantum sensing devices. One of the most challenging yet tantalising directions is to realize optical tweezers for atoms of different species. This will demonstrate the first species-selective optical tweezer, thus contributing to this exciting quest.