Abstract
The Schrödinger cat state produced differently in two directions is anticipated to be a critical quantum resource in quantum infor-mation technologies.By exploring the interplay between quantum nonreciprocity and topology in a one-dimensional microcavity array,we obtain the Schrödinger cat state(a pure quantum state)in a chosen direction at the edge cavity,whereas a classical state in the other direction.This nonreciprocal generation of the cat state originates from the topologically protected chirality-mode excitation in the nontrivial phase,but in the trivial phase,the nonreciprocal generation of cat state vanishes.Thus,our proposal is switchable by tuning the parameters so that a topological phase transition occurs.Moreover,the obtained cat state has nonreciprocal high fidelity,nonclassicality,and quantum coherence,which are sufficient to be used in various one-way quantum technologies,e.g.,invisible quantum sensing,noise-tolerant quantum computing,and chiral quantum networks.Our work pro-vides a general approach to control quantum nonreciprocities with the topological effect,which substantially broadens the fields of nonreciprocal photonics and topological physics.
万方数据