# Efficient and tunable Aharonov-Bohm quantum heat engine

## TL;DR

This paper introduces a tunable quantum heat engine based on an Aharonov-Bohm interferometer, achieving high thermoelectric efficiency and power output, with performance stability across various parameters, promising for experimental realization.

## Contribution

It presents a novel, tunable quantum heat engine design using an Aharonov-Bohm interferometer with high efficiency and stability, advancing thermoelectric device technology.

## Key findings

- Achieves thermopower up to 0.3 mV/K.
- Exceeds unity in $ZT$ values, indicating high efficiency.
- Efficiency at maximum power approaches 30% of Carnot limit.

## Abstract

We propose a quantum heat engine based on an Aharonov-Bohm interferometer in a two-terminal geometry, and investigate its thermoelectric performances in the linear response regime. Sizeable thermopower (up to $\sim 0.3\,\text{mV}$/K) as well as $ZT$ values largely exceeding unity can be achieved by simply adjusting parameters of the setup and temperature bias across the interferometer leading to thermal efficiency at maximum power approaching $30\%$ of the Carnot limit. This is close to the optimal efficiency at maximum power achievable for a two-terminal heat engine. Changing the magnetic flux, the asymmetry of the structure, a side-gate bias voltage through a capacitively-coupled electrode and the transmission of the T-junctions connecting the AB ring to the contacts allows to finely tune the operation of the quantum heat engine. The exploration of the parameters' space demonstrates that the high performances of the Aharonov-Bohm two-terminal device as a quantum heat engine are stable over a wide range of temperatures and length imbalances, promising towards experimental realization.