Title: Single atom energy-conversion device with a quantum load Show Chinese title

Title: 单原子能量转换装置与量子负载

Abstract: This work reports the functioning of a single atom energy-conversion device, operating either as a quantum engine or a refrigerator, coupled to a quantum load. The "working fluid" is comprised of two optical levels of a single ion, and the load is one vibrational mode of the same ion cooled down to the quantum regime. The energy scales of these two modes differ by 9 orders of magnitude. We realize cyclic energy transfers between the working fluid and the quantum load, either increasing or decreasing the population of the vibrational mode. This is achieved albeit the interaction between the load and the working fluid leads to a significant population redistribution and quantum correlations between them. The performance of the engine cycles as a function of several parameters is examined, and found to be in agreement with theory. We specifically look at the ergotropy of the load, which indicates the amount of energy stored in the load that can be extracted with a unitary process. We show that ergotropy rises with the number of engine cycles despite an increase in the entropy of the load. Our experiment represents the first fully quantum 4-stroke energy-conversion device operating with a generic coupling to a quantum load. Show Chinese abstract

Abstract: 这项工作报告了一个单原子能量转换装置的运行情况，该装置可作为量子发动机或冰箱运行，并连接到一个量子负载上。 "工作流体"由单个离子的两个光学能级组成，负载是同一离子的一个振动模式，该模式被冷却到量子区域。 这两个模式的能量尺度相差9个数量级。 我们实现了工作流体与量子负载之间的循环能量转移，无论是增加还是减少振动模式的粒子数。 尽管负载与工作流体之间的相互作用导致了显著的粒子数重新分布和它们之间的量子关联，但仍实现了这一点。 我们研究了发动机循环在几个参数下的性能，并发现与理论一致。 我们特别关注负载的功量，这表明了可以通过单位过程从负载中提取的能量量。 我们证明了即使负载的熵增加，功量也会随着发动机循环次数的增加而增加。 我们的实验代表了第一个完全量子化的四冲程能量转换装置，该装置与量子负载具有通用耦合。