Quantifying Decoherence of Gaussian Noise Channels

Abstract

Gaussian noise channels (also called classical noise channels, bosonic Gaussian channels) arise naturally in continuous variable quantum information and play an important role in both theoretical analysis and experimental investigation of information transmission. After reviewing concisely the basic properties of these channels, we introduce an information-theoretic measure for the decoherence of optical states caused by these channels in terms of averaged Wigner-Yanase skew information, explore its basic features, obtain a scaling law, and derive a complementarity relation between the decoherence and the quantum affinity. As an application of the decoherence measure, we derive a convenient and sufficient criterion for detecting optical nonclassicality. The decoherence on some typical optical states caused by Gaussian noise channels are explicitly evaluated to illustrate the concept.