Sub-Poissonian number differences in four-wave mixing of matter waves

TL;DR

This paper demonstrates sub-Poissonian number differences in four-wave mixing of Bose-Einstein condensates, highlighting potential for quantum-enhanced measurements and nonlocality tests.

Contribution

It reports the first observation of sub-Poissonian atom number differences in four-wave mixing of matter waves, advancing quantum metrology and nonlocality research.

Findings

Sub-Poissonian noise in opposing zones of scattering halo

Shot noise describes nonopposing zones

Potential for sub shot-noise interferometry

Abstract

We demonstrate sub-Poissonian number differences in four-wave mixing of Bose-Einstein condensates of metastable helium. The collision between two Bose-Einstein condensates produces a scattering halo populated by pairs of atoms of opposing velocities, which we divide into several symmetric zones. We show that the atom number difference for opposing zones has sub-Poissonian noise fluctuations whereas that of nonopposing zones is well described by shot noise. The atom pairs produced in a dual number state are well adapted to sub shot-noise interferometry and studies of Einstein-Podolsky-Rosen-type nonlocality tests.