# Quantum heat engine with a quadratically coupled optomechanical system

## TL;DR

This paper introduces a quantum heat engine utilizing a quadratically coupled optomechanical system, demonstrating enhanced power output due to quantum squeezing effects compared to linear counterparts.

## Contribution

It presents a novel quantum heat engine model based on quadratic optomechanical interaction, analyzing its performance and showing improved power output from squeezing effects.

## Key findings

- Engine operates as an effective four-stroke Otto cycle.
- Quadratic coupling yields higher power than linear coupling.
- Mechanical mode reaches a thermal-squeezed steady state.

## Abstract

We propose a quantum heat engine based on a quadratically coupled optomechanical system. The optical component of the system is driven periodically with an incoherent thermal drive, which induces periodic oscillations in the mechanical component. Under the action of the quadratic optomechanical interaction, the mechanical mode evolves from an initial thermal state to a thermal-squeezed steady state, as verified by calculating the Wigner functions. The dynamics of the system is identified as an effective four-stroke Otto cycle. We investigated the performance of the engine by evaluating the dissipated power, the maximum power under a load, and the maximum extractable work. It is found that the engine operating with quadratic optomechanics is more powerful than the one operating with linear optomechanics. The effect is explained by the presence of squeezing in the quantum state of the mechanical mode.