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

Speaker:  Dr Jie Ren(任杰),University of Leeds

Time: 10:30 am, June 13 (Friday), 2025

Place: Room M830, IOP-CAS (中国科学院物理研究所M830)

Abstract:

Mechanisms that give rise to coherent quantum dynamics, such as quantum manybody scars, have recently attracted much interest as a way of controlling quantumchaos.However, identifying the presence of quantum scars in general many-bodyHamiltonians remains an outstanding challenge. Here we introduce ScarFinder [1], avariational framework that reveals possible scar-like dyamics without priorknowledge of scar states or their algebraic structure. By iteratively evolving andprojecting states within a low-entanglement variational manifold, ScarFinder isolatesscarred trajectories by suppressing thermal contributions. We validate the method onthe analytically tractable spin-1 XY model [2], recovering the known scar dynamics,as well as the mixed field Ising model, where we capture and generalize the initialconditions previously associated with "weak thermalization" [3]. We then apply themethod to the PXP model [4] of Rydberg atom arrays, efciently characterizing itsmixed phase space and finding a previously unknown trajectory with nearly-perfectrevival dynamics in the thermodynamic limit, Our results establish ScarFinder as apowerful, model-agnostic tool for identifying and optimizing coherent dynamics inquantum many-body systems.

References:
[1]arXiv:2504.12383
[2]M.Schecter et al., PRL.123,147201(2019)
[3]M.C.Bañuls et al.,PRL.106.050405(2011)
[4]C.J. Turner et al., Nat. Phys.14,745(2018)