# Ultra-cold Single-Atom Quantum Heat Engines

## TL;DR

This paper proposes a scheme for implementing single-atom quantum heat engines using ultra-cold atom technology, demonstrating the feasibility of Carnot, Otto, and Diesel engines with realistic parameters and analyzing their performance limits.

## Contribution

It introduces a practical scheme for ultra-cold atom-based quantum heat engines and explores their performance, including effects of friction and super-adiabatic protocols.

## Key findings

- Carnot, Otto, and Diesel engines are feasible with current ultra-cold atom technology.
- Friction effects limit maximum performance in realistic implementations.
- Super-adiabatic transformations can optimize power extraction while maintaining high efficiency.

## Abstract

We propose a scheme for a single-atom quantum heat engine based on ultra-cold atom technologies. Building on the high degree of control typical of cold atom systems, we demonstrate that three paradigmatic heat engines -- Carnot, Otto and Diesel -- are within reach of state-of-the-art technology, and their performances can be benchmarked experimentally. We discuss the implementation of these engines using realistic parameters and considering the friction effects that limit the maximum obtainable performances in real-life experiments. We further consider the use of super-adiabatic transformations that allow to extract a finite amount of power keeping maximum (real) efficiency, and consider the energetic cost of running such protocols.