Optimizing energy conversion with nonthermal resources in steady-state quantum devices

TL;DR

This paper develops a framework for optimizing energy conversion in quantum devices using nonthermal resources, enhancing efficiency and precision beyond thermal limits, with practical implications for nanoelectronics.

Contribution

It introduces a novel optimization method for quantum energy converters fed by nonthermal resources, identifying transmission properties for optimal performance.

Findings

Performance surpasses thermal resource-based devices.

Optimization improves efficiency and precision.

Applicable to nanoelectronic device design.

Abstract

We provide a framework for optimizing energy conversion processes in coherent quantum conductors fed by nonthermal resources. Such nonthermal resources, which cannot be characterized by temperatures or electrochemical potentials, occur in small-scale systems that are smaller than their thermalization length. Using scattering theory in combination with a Lagrange multiplier method, we optimize the device's performance based on the efficiency, precision, or a trade-off between the two at a given output current. The transmission properties leading to this optimal performance are identified. We showcase our findings with the example of a refrigerator exploiting experimentally relevant nonthermal resources, which could result from competing environments or from light irradiation. We show that the performance is improved compared to a device exploiting a thermal resource. Our results can serve as guidelines for the design of energy-conversion processes in future nanoelectronic devices.