Cavity QED Detection of Interfering Matter Waves

TL;DR

This paper demonstrates the detection of matter wave interference from single atoms using a high-finesse optical cavity, revealing both wave and particle aspects of matter in a double-slit experiment with Bose-Einstein condensates.

Contribution

It introduces a novel cavity QED detection method for observing matter wave interference at the single-atom level.

Findings

Successful observation of matter wave interference from single atoms.

Realization of quantum measurement projecting atoms into definite states.

Evidence of both wave and particle nature of matter.

Abstract

We observe the build-up of a matter wave interference pattern from single atom detection events in a double-slit experiment. The interference arises from two overlapping atom laser beams extracted from a Rubidium Bose-Einstein condensate. Our detector is a high-finesse optical cavity which realizes the quantum measurement of the presence of an atom and thereby projects delocalized atoms into a state with zero or one atom in the resonator. The experiment reveals simultaneously the granular and the wave nature of matter.