Entanglement and asymmetric steering over two octaves of frequency difference with cascaded harmonic generation

TL;DR

This paper investigates a nonlinear optical system that employs cascaded nonlinearities to generate harmonic outputs, demonstrating bipartite entanglement and asymmetric EPR-steering across a broad frequency range using quantum equations.

Contribution

It introduces a quantum analysis of cascaded harmonic generation showing entanglement and steering over two octaves, a novel demonstration in nonlinear optics.

Findings

Quadrature squeezed outputs are produced.

Bipartite entanglement and EPR-steering are observed.

Asymmetric steering occurs across two octaves.

Abstract

We analyse a nonlinear optical system which uses cascaded nonlinearities to produce both second and fourth harmonic outputs from an input field at the fundamental frequency. Using fully quantum equations of motion, we show that the system produces quadrature squeezed outputs which exhibit bipartite entanglement, EPR-steering, and asymmetric steering across a two octave frequency range.