Work

Nonanaliticities and ergodicity breaking in noninteracting many-body dynamics via stochastic resetting and global measurements

Year: 2025

Type: preprint

Abstract: Stochastic resetting generates nonequilibrium steady states by interspersing unitary quantum dynamics with resets at random times. When the state to which the system is reset is chosen conditionally on the outcome of a global and spatially resolved measurement, the steady state can feature collective behavior similar to what is typically observed at phase transitions. Here we investigate such conditional reset protocol in a system of noninteracting spins, where the reset state is chosen as a magnetization eigenstate, that is selected (conditioned) on the outcome of a previous magnetization measurement. The stationary states that emerge from this protocol are characterized by the density of spins in a given magnetization eigenstate, which is the analogue of the order parameter. The resulting stationary phase diagram features multiple nonanalytic points. They are of first-order type for half-integer spin, while multicritical behavior, signalled by both first and second-order discontinuities, is found for integer spin. We also show that the associated dynamics is nonergodic, i.e., which stationary state the system ultimately assumes is determined be the initial state. Interestingly, the mechanism underlying these phenomena does not rely on interactions, but the emergent nonlinear behavior is solely a consequence of correlations induced by the measurement.

Source: arXiv (Cornell University)

Authors: Soldner, David, Lesanovsky, Igor, Perfetto, Gabriele

Institutions: University of Tübingen, University of Nottingham, Institute for Theoretical Physics

Language: English

Topic: Quantum many-body systems

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Deutsche Forschungsgemeinschaft, QuantERA, Horizon 2020 Framework Programme, HORIZON EUROPE European Research Council

Awards: Kollektive Quantenphänomene in dissipativen Systemen Wege zur Anwendung von Zeitkristallen in Sensorik und Metrologie, G1771891252, G1862646656, FOR 5522: Quantenthermalisierung, Lokalisierung und eingeschränkte Dynamik mit wechselwirkenden ultrakalten Atomen, Open 2D Quantum Simulator, G2744928646, G3559029362, Nichtgleichgewichtsphasenübergänge in offenen Quantensystemen mit absorbierenden Zuständen, FOR 5413: Quantenspinsysteme mit langreichweitigen Wechselwirkungen: Experiment, Theorie und Mathematik, G5271502856, G575169067, G7366365150

OpenAlex ID: W7091186876

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