# Holographic Heat Engines as Quantum Heat Engines

## TL;DR

This paper explores the connection between holographic heat engines, derived from Einstein's equations in anti-de Sitter spacetime, and quantum heat engines, proposing that certain black hole cycles can serve as models for quantum thermodynamic processes.

## Contribution

It introduces the idea that holographic heat engines can model quantum heat engines and presents novel black hole Otto and Diesel cycles with efficiency formulas similar to those of quantum and classical engines.

## Key findings

- Black hole Otto and Diesel cycles are constructed and analyzed.
- Efficiency formulas resemble those of quantum and classical heat engines.
- Potential for holographic models to inform quantum thermodynamics.

## Abstract

Certain solutions of Einstein's equations in anti-de Sitter spacetime can be engineered, using extended gravitational thermodynamics, to yield `holographic heat engines', devices that turn heat into useful mechanical work. On the other hand, there are constructions (both experimental and theoretical) where a series of operations is performed on a small quantum system, defining what are known as `quantum heat engines'. We propose that certain holographic heat engines can be considered models of quantum heat engines, and the possible fruitfulness of this connection is discussed. Motivated by features of quantum heat engines that take a quantum system through analogues of certain classic thermodynamic cycles, some black hole Otto and Diesel cycles are presented and explored for the first time. In the expected regime of overlap, our Otto efficiency formulae are of the form exhibited by quantum and classical heat engines.