# Single-Temperature Quantum Engine Without Feedback Control

## TL;DR

This paper proposes a quantum engine that operates at a single temperature, powered by quantum measurement, without needing feedback control, and analyzes its work, heat, and efficiency.

## Contribution

It introduces a novel quantum engine design that functions without feedback control and derives general expressions for its thermodynamic quantities.

## Key findings

- Engine operates at a single temperature using quantum measurement.
- Derived formulas for work, heat, and efficiency.
- Examples include spin in magnetic field and particle in changing potential.

## Abstract

A cyclically working quantum mechanical engine that operates at a single temperature is proposed. Its energy input is delivered by a quantum measurement. The functioning of the engine does not require any feedback control. We analyze work, heat, and the efficiency of the engine for the case of a working substance that is governed by the laws of quantum mechanics and that can be adiabatically compressed and dilated. The obtained general expressions are exemplified for a spin in an adiabatically changing magnetic field and a particle moving in a potential with slowly changing shape.