2026/07/21 by Polina Kofman, Elvira Bilokon, Valeriia Bilokon +1
#quant-ph
Continuous measurement is commonly associated with decoherence and the loss of symmetry. Here, we show that weak continuous measurements can instead act selectively: depending on the measured observable, they may either preserve or remove a dynamical relation between initially mirrored states. Using tunneling between the |+1⟩ and |-1⟩ states of a spin-1 system, we demonstrate that measurements of Sx and Sy break the symmetry of the tunneling dynamics in the presence of a longitudinal bias, whereas measurement of Sz leaves it intact. We formulate this behavior within the Lindblad framework, support it with numerical simulations, and reproduce the dissipative dynamics in a two-qubit quantum circuit using Trotterized evolution and stochastic collective rotations. Our results establish continuous measurement as a selective tool for controlling dynamical symmetry in open quantum systems.