Emergence of Non-Gaussian Coherent States Through Nonlinear Interactions

TL;DR

This paper investigates how nonlinear light-matter interactions induce non-Gaussian features in coherent states, revealing quantum properties like negative Wigner function regions while preserving Poissonian statistics, with implications for quantum optics.

Contribution

It demonstrates that nonlinear interactions naturally produce non-Gaussian coherent states with quantum advantages, expanding understanding of quantum state evolution in classical-like light.

Findings

Negative Wigner function regions emerge during evolution.

Coherent states retain Poissonian photon statistics.

States can reach Heisenberg-limited metrological advantage.

Abstract

Light-matter interactions that are nonlinear with respect to the photon number reveal the true quantum nature of coherent states. We characterize how coherent states depart from Gaussian by the emergence of negative values in their Wigner function during the evolution while maintaining their characteristic Poissonian photon statistics. Such states have non-minimum uncertainty yet present a metrological advantage that can reach the Heisenberg limit. Non-Gaussianity of light arises as a general property of nonlinear interactions, which only requires a polarizable media, resonant or dispersive. Our results highlight how useful quantum features can be extracted from the seemingly most classical states of light, a relevant phenomenon for quantum optics applications.