# No thermalization without correlations

## TL;DR

This paper proves that quantum systems require persistent correlations with their environment to thermalize, challenging previous assumptions and proposing a new method to model baths that produce thermal states.

## Contribution

It demonstrates that correlations are essential for thermalization in quantum systems and introduces a systematic way to construct translation invariant bath models.

## Key findings

- Correlations are necessary for quantum thermalization.
- A systematic procedure for bath model construction is proposed.
- A quantum optical scheme for experimental validation is outlined.

## Abstract

The proof of the long-standing conjecture is presented that Markovian quantum master equations are at odds with quantum thermodynamics under conventional assumptions of fluctuation-dissipation theorems (implying a translation invariant dissipation). Specifically, except for identified systems, persistent system-bath correlations of at least one kind, spatial or temporal, are obligatory for thermalization. A systematic procedure is proposed to construct translation invariant bath models producing steady states that well-approximate thermal states. A quantum optical scheme for the laboratory assessment of the developed procedure is outlined.