Collectively enhanced thermalization via multiqubit collisions

TL;DR

This paper explores how multiple random collisions with multiqubit clusters can enhance the thermalization process of a target qubit, leading to quantum advantages such as faster thermalization and higher effective temperatures, with potential experimental implementations.

Contribution

It introduces the concept of quantum super-thermalization, showing how multiqubit collisions can significantly accelerate thermalization and increase temperature, depending on cluster states.

Findings

Target qubit can reach thermal states with enhanced temperature proportional to N^2.

Thermalization time can be reduced by a factor of N^2 with proper cluster coherence.

Effects analogous to super-radiance are observed in thermalization dynamics.

Abstract

We investigate the evolution of a target qubit caused by its multiple random collisions with $N$-qubit clusters. Depending on the cluster state, the evolution of the target qubit may correspond to its effective interaction with a thermal bath, a coherent (laser) drive, or a squeezed bath. In cases where the target qubit relaxes to a thermal state its dynamics can exhibit a quantum advantage, whereby the target-qubit temperature can be scaled up proportionally to $N^2$ and the thermalization time can be shortened by a similar factor, provided the appropriate coherence in the cluster is prepared by non-thermal means. We dub these effects quantum super-thermalization due to its analogies to super-radiance. Experimental realizations of these effects are suggested.