# Quantum speed limits for an open system in contact with a thermal bath

## TL;DR

This paper establishes fundamental bounds on the speed of quantum evolution for open systems interacting with thermal baths, applicable beyond weak coupling and without relying on Markovian assumptions.

## Contribution

It introduces rigorous, expectation-value-based bounds on quantum speed limits for open systems that do not depend on the Markov approximation.

## Key findings

- Bounds are valid for strong and weak system-bath coupling regimes.
- The bounds are expressed in terms of few-body observables.
- Results extend the understanding of quantum dynamics beyond traditional approximations.

## Abstract

We prove fundamental rigorous bounds on the speed of quantum evolution for a quantum system coupled to a thermal bath. The bounds are formulated in terms of expectation values of few-body observables derived from the system-bath Hamiltonian. They do not rely on the Markov approximation and, as a consequence, are applicable beyond the limit of weak system-bath coupling.