Measurement-Selective Dynamical Symmetry Breaking

Abstract: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 $|+1\rangle$ and $|-1\rangle$ states of a spin-1 system, we demonstrate that measurements of $S_x$ and $S_y$ break the symmetry of the tunneling dynamics in the presence of a longitudinal bias, whereas measurement of $S_z$ 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.

arXiv:2607.19582 [quant-ph]

(or arXiv:2607.19582v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2607.19582 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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