Measurement-induced symmetry restoration and quantum Mpemba effect

• URL: http://arxiv.org/abs/2502.19506v1
• Date: Wed, 26 Feb 2025 19:12:04 GMT
• Title: Measurement-induced symmetry restoration and quantum Mpemba effect
• Authors: Giuseppe Di Giulio, Xhek Turkeshi, Sara Murciano,
• Abstract summary: We show that dynamical measurements strongly influence the evolution of symmetry in many-body quantum systems.<n>We uncover a novel measurement-induced symmetry restoration mechanism.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Monitoring a quantum system can profoundly alter its dynamical properties, leading to nontrivial emergent phenomena. In this work, we demonstrate that dynamical measurements strongly influence the evolution of symmetry in many-body quantum systems. Specifically, we demonstrate that monitored systems governed by non-Hermitian dynamics exhibit a quantum Mpemba effect, where systems with stronger initial asymmetry relax faster to a symmetric state. Crucially, this phenomenon is purely measurement-induced: in the absence of measurements, we find states where the corresponding unitary evolution does not display any Mpemba effect. Furthermore, we uncover a novel measurement-induced symmetry restoration mechanism: below a critical measurement rate, the symmetry remains broken, but beyond a threshold, it is fully restored in the thermodynamic limit--along with the emergence of the quantum Mpemba effect.

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