Quantum many-body scars in random unitary circuits
Quantum Physics
2026-04-21 v1 Statistical Mechanics
Abstract
Quantum many-body scars are rare exceptions to thermalization: they sustain non-thermal stationary states without the protection of any local conservation law, and are generally expected to be fragile. Here we construct an analytically tractable random unitary circuit hosting a single scar, and derive from first principles the thermalization mechanism governing perturbations thereof - described by a picture of fluctuating interfaces. Surprisingly, despite being thermodynamically irrelevant for local observables, the scar leaves a sharp fingerprint in the entanglement dynamics, driving a transition as a function of perturbation strength that is not probed by any local measurement.
Cite
@article{arxiv.2604.18244,
title = {Quantum many-body scars in random unitary circuits},
author = {Luca Capizzi and Benoît Ferté},
journal= {arXiv preprint arXiv:2604.18244},
year = {2026}
}