Extracting Work from a Single Heat Bath via Vanishing Quantum Coherence

Abstract

We present here a quantum Carnot engine in which the atoms in the heat bath are given a small bit of quantum coherence. The induced quantum coherence becomes vanishingly small in the high-temperature limit at which we operate and the heat bath is essentially thermal. However, the phase phi, associated with the atomic coherence, provides a new control parameter that can be varied to increase the temperature of the radiation field and to extract work from a single heat bath. The deep physics behind the second law of thermodynamics is not violated; nevertheless, the quantum Carnot engine has certain features that are not possible in a classical engine.

Implications of Coupling in Quantum Thermodynamic Machines

“…Such a study helps us to understand the special behavior of thermodynamic quantities like work, heat, and efficiency in the quantum regime due to the presence non-classical features such as entanglement, quantum superposition, squeezing, etc. [19][20][21]. The quantum heat devices can show interesting atypical behaviors such as exceeding Carnot limit [19,21] when they act as heat engines.…”

“…[19][20][21]. The quantum heat devices can show interesting atypical behaviors such as exceeding Carnot limit [19,21] when they act as heat engines. However, these apparent behaviors are found to be compatible with the second law of thermodynamics when all the preparation costs are considered [22].…”

Revisiting the quantum Szilard engine with fully quantum considerations

“…Research interests in the SZE have recently been revived in various theoretical contexts [12][13][14][15][16] and experimental implementations [17][18][19]. However, early literatures hardly paid attention to fully quantum analysis except for those via measurement process [20,21].…”

Analysis of Quantum Coherent Semiconductor Quantum Dotp−i−nJunction Photovoltaic Cells

“…Scully also indicates in [1] that there is a relation between the physics of his proposed photo-Carnot quantum heat engine [6] and the proposed quantum coherent p-i-n junction quantum dot PV cell (presented in [1]). The key component of the photo-Carnot quantum heat engine is the concept of a new, specialized, coherent working fluid: "phaseonium" [6].…”

“…The key component of the photo-Carnot quantum heat engine is the concept of a new, specialized, coherent working fluid: "phaseonium" [6]. Sunlight (the working fluid analog to "phaseonium") is incoherent and thus does not adopt "phaseonium"…”