Misra Avijit, Opatrný Tomáš, Kurizki Gershon
AMOS and Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel and International Center of Quantum Artificial Intelligence for Science and Technology (QuArtist) and Department of Physics, Shanghai University, 200444 Shanghai, China.
Department of Optics, Faculty of Science, Palacký University, 17. listopadu 50, 77146 Olomouc, Czech Republic.
Phys Rev E. 2022 Nov;106(5-1):054131. doi: 10.1103/PhysRevE.106.054131.
Our goal in this article is to elucidate the rapport of work and information in the context of a minimal quantum-mechanical setup: a converter of heat input to work output, the input consisting of a single oscillator mode prepared in a hot thermal state along with a few much colder oscillator modes. The core issues we consider, taking account of the quantum nature of the setup, are as follows: (i) How and to what extent can information act as a work resource or, conversely, be redundant for work extraction? (ii) What is the optimal way of extracting work via information acquired by measurements? (iii) What is the bearing of information on the efficiency-power tradeoff achievable in such setups? We compare the efficiency of work extraction and the limitations of power in our minimal setup by different, generic, measurement strategies of the hot and cold modes. For each strategy, the rapport of work and information extraction is found and the cost of information erasure is allowed for. The possibilities of work extraction without information acquisition, via nonselective measurements, are also analyzed. Overall, we present, by generalizing a method based on optimized homodyning that we have recently proposed, the following insight: extraction of work by observation and feedforward that only measures a small fraction of the input is clearly advantageous to the conceivable alternatives. Our results may become the basis of a practical strategy of converting thermal noise to useful work in optical setups, such as coherent amplifiers of thermal light, as well as in their optomechanical and photovoltaic counterparts.
在本文中，我们的目标是在一个最小化的量子力学装置背景下阐明功与信息的关系：一个将热输入转换为功输出的装置，其输入由处于热平衡态的单个振荡模式以及几个温度低得多的振荡模式组成。考虑到该装置的量子性质，我们所考虑的核心问题如下：（i）信息如何以及在何种程度上可以作为一种功资源，或者相反，对于功的提取是冗余的？（ii）通过测量获得的信息来提取功的最优方式是什么？（iii）信息对于在此类装置中可实现的效率 - 功率权衡有何影响？我们通过对热模式和冷模式采用不同的、通用的测量策略，比较了我们最小化装置中功提取的效率和功率限制。对于每种策略，我们找出了功与信息提取的关系，并考虑了信息擦除的成本。我们还分析了通过非选择性测量在不获取信息的情况下提取功的可能性。总体而言，通过推广我们最近提出的基于优化零差检测的方法，我们得出以下见解：仅对一小部分输入进行测量的观测和前馈功提取明显优于其他可设想的方法。我们的结果可能成为在光学装置（如热光的相干放大器）及其光机械和光伏对应装置中将热噪声转换为有用功的实用策略的基础。
