Deterministic secure quantum communication under vacuum fluctuation

Abstract

A real quantum system is unavoidably affected by external environment, which would produce noise or decoherence, and reduce the efficiency of quantum communication in realistic circumstance. In this paper, we present a noisy deterministic secure quantum communication (DSQC) scheme. We find that fidelity has close relation with quantum coherence and declines to a stable value with decoherent time. Small two-atom distance can improve the fidelity and coherence, and a reflecting boundary can effectively inhibit fidelity and coherence from degradation under the effect of vacuum fluctuation. Our study would be helpful to promote the communication efficiency of open quantum system.