High-order optical nonlinearity at low light levels

TL;DR

This paper reports the observation of a high-order nonlinear optical process in cold atomic gases, achieving the largest fifth-order susceptibility and enabling efficient six-wave mixing at low light levels, with potential quantum applications.

Contribution

It demonstrates a novel high-order nonlinearity in cold atoms with large susceptibility and efficient low-light-level six-wave mixing, advancing quantum optics research.

Findings

Largest reported fifth-order nonlinear susceptibility  = 1.9x10^{-12} (m/V)^4

High transparency in the nonlinear process

Efficient six-wave-mixing at low-light levels

Abstract

We observe a nonlinear optical process in a gas of cold atoms that simultaneously displays the largest reported fifth-order nonlinear susceptibility \chi^(5) = 1.9x10^{-12} (m/V)^4 and high transparency. The nonlinearity results from the simultaneous cooling and crystallization of the gas, and gives rise to efficient Bragg scattering in the form of six-wave-mixing at low-light-levels. For large atom-photon coupling strengths, the back-action of the scattered fields influences the light-matter dynamics. This system may have important applications in many-body physics, quantum information processing, and multidimensional soliton formation.