Measurement-induced multipartite-entanglement regimes in collective spin systems

Poggi, Pablo M. and Muñoz-Arias, Manuel H. (2024) Measurement-induced multipartite-entanglement regimes in collective spin systems. Quantum, 8. 1229. ISSN 2521-327X (https://doi.org/10.48550/arXiv.2305.10209)

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Abstract

We study the competing effects of collective generalized measurements and interaction-induced scrambling in the dynamics of an ensemble of spin-1/2 particles at the level of quantum trajectories. This setup can be considered as analogous to the one leading to measurement-induced transitions in quantum circuits. We show that the interplay between collective unitary dynamics and measurements leads to three regimes of the average Quantum Fisher Information (QFI), which is a witness of multipartite entanglement, as a function of the monitoring strength. While both weak and strong measurements lead to extensive QFI density (i.e., individual quantum trajectories yield states displaying Heisenberg scaling), an intermediate regime of classical-like states emerges for all system sizes where the measurement effectively competes with the scrambling dynamics and precludes the development of quantum correlations, leading to sub-Heisenberg-limited states. We characterize these regimes and the crossovers between them using numerical and analytical tools, and discuss the connections between our findings, entanglement phases in monitored many-body systems, and the quantum-to-classical transition.

  • Item type:Article
    ID code:87809
    Dates:
    Date
    Event
    12 January 2024
    Published
    27 December 2023
    Accepted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:15 Jan 2024 12:39
    Last modified:02 May 2024 01:18
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/87809
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