Quantum thermal devices have attracted growing attentions since they can be used to manipulate the heat currents of macroscopic thermal baths in a microscopic scale. In the present work, a three-level system attached to three thermal baths with different temperatures is exploited to serve as a valve, a refrigerator, an amplifier, and a thermometer in the quantum regime, via tuning the inner coupling strength of the system and the temperatures of the external baths. We discuss the connections among these thermal functions in the steady state of this microscopic device with or without the inner coupling using the Redfield master equation under a partial secular approximation. It is found that the functions as valve, refrigerator and amplifier in this quantum model can be realized in a large parametric space. And a valve-associated thermometer of low-temperature can be established without the assistance from the inner coupling of the system as well as the quantum coherence in the steady state. A high sensitivity of the indirect measurement of the low temperature of the sample can be obtained due to its nonlinear dependence on the temperatures of both the hot and the work terminals. Our study of such a multifunctional thermal device allows to provide a deeper insight to the underlying quantum thermodynamics mechanism associated with the quantum coherence, which is induced by the inner coupling and demonstrated in the steady state of the three-level system. Also, our model is a concise instance for integrating multiple thermal functions into a single microscopic system.

中文翻译：

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一种多功能量子热器件：有无内耦合

量子热器件已引起越来越多的关注，因为它们可用于在微观尺度上操纵宏观热浴的热流。在目前的工作中，通过调整系统的内部耦合强度，利用连接到三个不同温度的温泉浴的三级系统作为量子体系中的阀门、冰箱、放大器和温度计。外部浴槽的温度。我们在部分长期近似下使用 Redfield 主方程讨论在有或没有内部耦合的微型设备的稳态下这些热函数之间的联系。发现该量子模型中的阀门、制冷机和放大器等功能可以在大参数空间中实现。无需系统内部耦合和稳态量子相干的辅助，即可建立低温阀相关温度计。由于其对热端和工作端温度的非线性依赖性，可以获得样品低温间接测量的高灵敏度。我们对这种多功能热器件的研究可以更深入地了解与量子相干相关的潜在量子热力学机制，量子相干是由内部耦合引起的，并在三能级系统的稳态中得到证明。此外，我们的模型是将多个热函数集成到单个微观系统中的简洁实例。