Bath-induced Zeno localization in driven many-body quantum systems

TL;DR

This paper demonstrates that strong bath coupling can induce localization in driven many-body quantum spin systems through the quantum Zeno effect, explaining experimental observations of thermal regime breakdown.

Contribution

It reveals how bath-induced localization occurs in ergodic many-body systems via the quantum Zeno effect, with implications for dynamic nuclear polarization.

Findings

Strong bath coupling causes spin localization despite ergodic eigenstates.

Hole-burning EPR spectrum indicates Zeno localization.

Explains thermal regime breakdown above 4-5 Kelvin.

Abstract

We study a quantum interacting spin system subject to an external drive and coupled to a thermal bath of spatially localized vibrational modes, serving as a model of Dynamic Nuclear Polarization. We show that even when the many-body eigenstates of the system are ergodic, a sufficiently strong coupling to the bath may effectively localize the spins due to many-body quantum Zeno effect, as manifested by the hole-burning shape of the electron paramagnetic resonance spectrum. Our results provide an explanation of the breakdown of the thermal mixing regime experimentally observed above 4 - 5 Kelvin.