Cooperative nonreciprocal emission and quantum sensing of symmetry breaking
Phys. Rev. B 113, 104434 – Published 18 March, 2026
DOI: https://doi.org/10.1103/s56h-xqqp
Abstract
Nonreciprocal propagation of energy and information is fundamental to a wide range of quantum technology applications. In this work, we explore the quantum many-body dynamics of a qubit ensemble coupled to a shared bath that mediates coherent and dissipative interqubit interactions with both symmetric and antisymmetric components. We find that the interplay between antisymmetric (symmetric) coherent and symmetric (antisymmetric) dissipative interactions results in nonreciprocal couplings, which, in turn, generate a spatially asymmetric emission pattern. We demonstrate that this pattern arises from nonreciprocal interactions coupling different quantum many-body states within a specific excitation manifold. Focusing on solid-state baths, we show that their lack of time-reversal and inversion symmetry is a key ingredient for generating nonreciprocal dynamics in the qubit ensemble. With the plethora of quantum materials that exhibit this symmetry breaking at equilibrium, our approach paves the way for realizing cooperative nonreciprocal transport in qubit ensembles without requiring time-modulated external drives or complex engineering. Using an ensemble of nitrogen-vacancy (NV) centers coupled to a generic noncentrosymmetric ferromagnetic bath as a concrete example, we demonstrate that our predictions can be tested in near-future experiments. Additionally, we find that the spatial asymmetry in the relaxation dynamics increases with the size of the qubit ensemble and persists over longer interqubit distances than the signatures of super- and subradiant collective relaxation dynamics. As the spatial asymmetry in the relaxation dynamics of the qubit ensemble is a direct probe of symmetry breaking in the solid-state bath, our work also opens the door to developing model-agnostic quantum sensing schemes capable of detecting bath properties invisible to current state-of-the-art protocols, which operate solid-state defects as single-qubit sensors.
