Tradeoffs in quantum thermometry: Consistent quantum thermodynamic frameworks

量子测温的权衡：一致的量子热力学框架

• 批准号: 580756-2022
• 负责人: Segal, DviraD
• 金额: $ 1.82万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748326
• 关键词: Tradeoffs; quantum; thermometry; Consistent; thermodynamic

The science of thermometry seems trivial; it was formulated in the 19th century as the zeroth law of thermodynamics. In classical macroscopic thermometry, a probe is brought into contact with a sample. By measuring a certain quantity of the probe, the temperature of the sample can be inferred. However, this intuitive protocol breaks down once quantum principles play a role, which is the situation for nanoscale probes and at low temperatures. This is because for small and quantum systems, thermalization does not necessarily take place, or it is happening yet on very long timescales. Moreover, temperature is not a quantum observable, and one needs to ponder on how to infer it under quantum evolution and when performing quantum measurements. Quantum effects can be orchestrated to enhance the precision and sensitivity of thermometry, for example by simultaneously operating and correlating multiple quantum probes. The objective of this proposal is to build on principles of quantum mechanics and devise nanoscale thermometers that are accurate, sensitive over a broad range of temperatures, fast, and operative at low cost. First, since quantum probes are small, their interaction with the sample alter them, for example, by changing their energetic, thus obstructing temperature estimation. We will asses the role of probe-sample interactions in thermometry, and correct for it. Second, temporal quantum coherences can be generated in a thermometer by the sample. We will utilize these coherences, which can be long-lived, to devise enhanced thermometry protocols that do not rely on the zero law of thermodynamics. Finally, we will optimize quantum thermometers against different measures by deriving tradeoff relations between their accuracy, sensitivity, cost, and duration. The work will contribute to the development of miniaturized temperature sensors and precise thermal conductance measurements. Application are e.g., for in situ imaging and sensing of biological systems and other dynamic environments, development and characterization of heat dissipation in electronic and thermoelectric devices, advancement of quantum computing hardware, and design of quantum heat machines, engines and refrigerators.

温度测量学看起来微不足道，它在世纪被表述为热力学第零定律。在经典的宏观测温法中，探针与样品接触。通过测量一定量的探针，可以推断出样品的温度。然而，一旦量子原理发挥作用，这种直观的协议就会崩溃，这是纳米探针和低温下的情况。这是因为对于小型和量子系统，热化不一定会发生，或者它在很长的时间尺度上发生。此外，温度不是量子可观测的，人们需要思考如何在量子演化和进行量子测量时推断它。量子效应可以被编排以提高温度测量的精度和灵敏度，例如通过同时操作和关联多个量子探针。该提案的目标是建立在量子力学原理的基础上，设计出精确、在广泛的温度范围内灵敏、快速、低成本的纳米级温度计。首先，由于量子探针很小，它们与样品的相互作用会改变它们，例如，通过改变它们的能量，从而阻碍温度估计。我们将评估探针-样品相互作用在温度测量中的作用，并对其进行修正。第二，时间量子相干可以在温度计中由样品产生。我们将利用这些可以长期存在的凝聚力来设计不依赖于热力学零定律的增强型测温协议。最后，我们将通过推导其准确性，灵敏度，成本和持续时间之间的权衡关系来优化量子温度计。这项工作将有助于小型化温度传感器和精确的热导测量的发展。应用例如，用于生物系统和其他动态环境的原位成像和传感，电子和热电设备中散热的开发和表征，量子计算硬件的进步以及量子热机，发动机和冰箱的设计。