Entanglement Transition in a Monitored Free-Fermion Chain: From Extended Criticality to Area Law

We analyze the quantum trajectory dynamics of free fermions subject to continuous monitoring. For weak monitoring, we identify a novel dynamical regime of subextensive entanglement growth, reminiscent of a critical phase with an emergent conformal invariance. For strong monitoring, however, the dyna...

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Bibliographic Details
Published inPhysical review letters Vol. 126; no. 17; p. 170602
Main Authors Alberton, O, Buchhold, M, Diehl, S
Format Journal Article
LanguageEnglish
Published United States 30.04.2021
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Summary:We analyze the quantum trajectory dynamics of free fermions subject to continuous monitoring. For weak monitoring, we identify a novel dynamical regime of subextensive entanglement growth, reminiscent of a critical phase with an emergent conformal invariance. For strong monitoring, however, the dynamics favors a transition into a quantum Zeno-like area-law regime. Close to the critical point, we observe logarithmic finite size corrections, indicating a Berezinskii-Kosterlitz-Thouless mechanism underlying the transition. This uncovers an unconventional entanglement transition in an elementary, physically realistic model for weak continuous measurements. In addition, we demonstrate that the measurement aspect in the dynamics is crucial for whether or not a phase transition takes place.
ISSN:1079-7114
DOI:10.1103/PhysRevLett.126.170602