Measurement induced faster symmetry restoration in quantum trajectories

by Ms Katha Ganguly (IISER PUNE)

Thursday 6 Aug 2026, 11:30 → 12:30 Asia/Kolkata

A304 and on Zoom

Symmetries play a central role in quantum systems by protecting robust physical features, enabling noise-resilient subspaces, and reducing the effective complexity of many-body systems. However, even when the governing dynamics respects a symmetry, individual quantum states may break it, limiting these advantages. In this talk, I will present how continuous measurement of  global and local observables can be used to restore U(1) symmetry in quantum trajectories. We show that under global monitoring, symmetry restoration is exponentially accelerated for initial states containing distant charge sectors, whereas states composed of adjacent charge sectors exhibit slow restoration. We further establish the universality of this behaviour across different measurement protocols. Finally, we show that local monitoring can overcome this slow restoration for certain states, achieving even faster relaxation.