Measurement-based Formulation of Quantum Heat Engine

TL;DR

This paper introduces a measurement-based quantum heat engine model that explicitly links energy transfer to measurable work, deriving a new trade-off relation between work measurability and quantum coherence.

Contribution

It proposes a novel measurement-based formulation of quantum heat engines, connecting microscopic quantum processes with macroscopic work measurement.

Findings

Derived a suitable energy conservation law for the model

Proposed a concrete submodel of the quantum heat engine

Established a trade-off relation between work measurability and quantum coherence

Abstract

There exist two formulations for quantum heat engine that models an energy transfer between two microscopic systems. One is semi-classical scenario, and the other is full quantum scenario. The former is formulated as a unitary evolution for the internal system, and is adopted by the community of statistical mechanics. In the latter, the whole process is formulated as unitary, and is adopted by the community of quantum information. This paper proposes a model for quantum heat engine that transfers energy from a collection of microscopic systems to a macroscopic system like a fuel cell. In such a situation, the amount of extracted work is visible for a human. For this purpose, we formulate quantum heat engine as the measurement process whose measurement outcome is the amount of extracted work. Under this model, we derive a suitable energy conservation law and propose a more concrete submodel. Then, we derive a novel trade-off relation between the measurability of the amount of work extraction and the coherence of the internal system, which examines the application of the semi-classical scenario to a heat engine transferring an energy from a collection of microscopic systems to a macroscopic system.