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arXiv · 2307.05685

Entanglement transitions and quantum bifurcations under continuous long-range monitoring

Angelo Russomanno·Giulia Piccitto·Davide Rossini
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Abstract

We study the asymptotic bipartite entanglement entropy of the quantum trajectories of a free-fermionic system, when subject to a continuous nonlocal monitoring. The measurements are described by Gaussian-preserving two-point operators, whose strength decays as a power-law with exponent $\alpha$. Different behaviors of the entanglement entropy with the system size emerge: for $\alpha$ below a given threshold value a volume-law behavior sets in, while for larger $\alpha$ we observe a transition from subvolume to area-law, whose exact location depends on the measurements rate and on the presence of a Hamiltonian dynamics. We also consider the expectation probability distribution of the measurement operators, and find that this distribution features a transition from a unimodal to a bimodal shape. We discuss the possible connections between this qualitative change of the distribution and the entanglement transition points.

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Angelo Russomanno, Giulia Piccitto, Davide Rossini. 2023-07-11. Entanglement transitions and quantum bifurcations under continuous long-range monitoring. https://doi.org/10.1103/physrevb.108.104313

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