Entanglement properties of degenerate four-wave mixing of matter-waves in a periodic potential

TL;DR

This paper analyzes the quantum entanglement generated in degenerate four-wave mixing of matter-waves within a periodic potential, highlighting its many-body nature and robustness, with implications for creating macroscopic entangled atomic samples.

Contribution

It demonstrates that entanglement arises as a genuine many-body effect in matter-wave four-wave mixing and shows its robustness against moderate seeding.

Findings

Entanglement is created between quadratures of scattered atomic clouds.

Significant violation of entanglement inequalities observed.

Entanglement is robust to moderate coherent seeding.

Abstract

In a recent experiment Campbell et al. [Phys. Rev. Lett. 96, 020406 (2006)] observed degenerate four-wave mixing of matter-waves in a one-dimensional optical lattice, a process with potential for generating entanglement among atoms. We analyse the essential quantum features of the experiment to show that entanglement is created between the quadratures of the two scattered atomic clouds and is a true many-body (rather than two-body) effect. We demonstrate a significant violation of entanglement inequalities that is robust to a moderate level of coherent seeding. The system is thus a promising candididate for generating macroscopically entangled atomic samples.