Year: 2025
Type: article
Abstract: The quantum relative entropy between a quantum state and its Gaussian equivalent is a quantifying function of the system's non-Gaussianity, a useful resource in several applications, such as quantum communication and computation. One of its most fundamental properties is to be monotonically decreasing under Gaussian evolutions. In this paper, we develop the conditions for a non-Gaussian quantum channel to preserve the monotonically decreasing property. We propose a necessary condition to classify between Gaussian and non-Gaussian channels and use it to define a class of quantum channels that decrease the system's non-Gaussianity. We also discuss how this property, combined with a restriction on the states at the channel's input, can be applied to the security analysis of continuous-variable quantum key distribution protocols.
Source: Entropy
DOI: 10.3390/e27070768
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4412518357