Efficient Measurement of Bosonic Non-Gaussianity

TL;DR

This paper introduces a new, efficient method for quantifying bosonic non-Gaussianity in quantum states, utilizing non-Gaussian entropy and a practical measurement protocol suitable for experimental implementation.

Contribution

It proposes a novel non-Gaussian entropy measure and a practical protocol for measuring it, extending the approach to mixed states in bosonic systems.

Findings

Introduces non-Gaussian entropy as a new quantifier.

Develops a measurement protocol using beam splitters and copies.

Provides a framework applicable to mixed states.

Abstract

Non-Gaussian states are essential resources in quantum information processing. In this work, we investigate methods for quantifying bosonic non-Gaussianity in many-body systems. Building on recent theoretical insights into the self-convolution properties of bosonic pure states, we introduce non-Gaussian entropy as a new measure to characterize non-Gaussianity in bosonic pure states. We further propose a practical protocol for measuring non-Gaussian entropy using three beam splitters and four copies of the input state. In addition, we extend this framework to mixed states, providing a general approach to quantifying non-Gaussianity. Our results offer a convenient and efficient method for characterizing bosonic non-Gaussianity, paving the way for its implementation on near-term experimental platforms.