Adiabatic quantum motors

TL;DR

This paper develops a comprehensive theory of adiabatic quantum motors, explaining how a transport current can drive periodic variations in a quantum system, with implications for efficiency and quantum interference effects.

Contribution

It introduces a general theoretical framework for adiabatic quantum motors, linking quantum pumping characteristics to motor operation and efficiency, including chaotic and Thouless pump-based motors.

Findings

Quantum motors can operate via quantum interference effects.

Thouless pump-based motors achieve ideal efficiency.

Quantum interference enables motor operation without classical bias.

Abstract

When parameters are varied periodically, charge can be pumped through a mesoscopic conductor without applied bias. Here, we consider the inverse effect in which a transport current drives a periodic variation of an adiabatic degree of freedom. This provides a general operating principle for adiabatic quantum motors, for which we develop a comprehensive theory. We relate the work performed per cycle on the motor degree of freedom to characteristics of the underlying quantum pump and discuss the motor's efficiency. Quantum motors based on chaotic quantum dots operate solely due to quantum interference, motors based on Thouless pumps have ideal efficiency.