More bang for your buck: Towards super-adiabatic quantum engines

TL;DR

This paper demonstrates that using shortcuts to adiabaticity in a quantum Otto cycle allows for finite power operation at zero friction, advancing quantum engine efficiency beyond traditional limits.

Contribution

It introduces a method to implement frictionless quantum engines operating at finite power using shortcuts to adiabaticity.

Findings

Quantum shortcuts enable frictionless, finite-power cycles.

Harmonic oscillator quantum Otto cycle exemplifies the approach.

Potential for more efficient quantum engines at nanoscale.

Abstract

The reversible nature of thermodynamical cycles is an idealisation based on the assumption of perfect quasi-static dynamics. As a consequence of this assumption, ideal engines operate at the maximum efficiency but have zero power. Realistic engines, on the other hand, operate in finite-time and are intrinsically irreversible, implying friction effects at short cycle times. The engineering goal is to find the maximum efficiency allowed at the maximum possible power. In the current technological age, with our ability to manipulate devices at the nanoscale and beyond, one must understand the consequences of engines which operate at the quantum mechanical level. In this domain one cannot avoid the emergence of both quantum and thermal fluctuations which drastically alter the energetics of the cycle. Very recently, it has been shown that the Hamiltonian of a quantum system may be manipulated in such a way as to mimic an adiabatic process via a non-adiabatic shortcut. A surge of experimental progress has demonstrated several of these proposals in the laboratory. In this paper we show that, by utilising shortcuts to adiabaticity in a quantum engine cycle, one can engineer a thermodynamical cycle working at finite power and zero friction. Our findings are elucidated using a harmonic oscillator undergoing a quantum Otto cycle.