ScarFinder: a detector of optimal scar trajectories in quantum many-body dynamics

• URL: http://arxiv.org/abs/2504.12383v1
• Date: Wed, 16 Apr 2025 18:00:01 GMT
• Title: ScarFinder: a detector of optimal scar trajectories in quantum many-body dynamics
• Authors: Jie Ren, Andrew Hallam, Lei Ying, Zlatko Papić,
• Abstract summary: Mechanisms that give rise to coherent quantum dynamics, such as quantum many-body scars, have recently attracted much interest.<n>We introduce ScarFinder, a variational framework that reveals possible scar-like dynamics without prior knowledge of scar states or their structure.<n>Our results establish ScarFinder as a powerful, model-agnostic tool for identifying and optimizing coherent dynamics in quantum many-body systems.
• Score: 13.395133118438528
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Mechanisms that give rise to coherent quantum dynamics, such as quantum many-body scars, have recently attracted much interest as a way of controlling quantum chaos. However, identifying the presence of quantum scars in general many-body Hamiltonians remains an outstanding challenge. Here we introduce ScarFinder, a variational framework that reveals possible scar-like dynamics without prior knowledge of scar states or their algebraic structure. By iteratively evolving and projecting states within a low-entanglement variational manifold, ScarFinder isolates scarred trajectories by suppressing thermal contributions. We validate the method on the analytically tractable spin-1 XY model, recovering the known scar dynamics, as well as the mixed field Ising model, where we capture and generalize the initial conditions previously associated with ``weak thermalization''. We then apply the method to the PXP model of Rydberg atom arrays, efficiently characterizing its mixed phase space and finding a previously unknown trajectory with nearly-perfect revival dynamics in the thermodynamic limit. Our results establish ScarFinder as a powerful, model-agnostic tool for identifying and optimizing coherent dynamics in quantum many-body systems.

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