Abstract

50 years ago astronomers Robert Hanbury Brown and Richard Twiss
discovered photon bunching in the light emitted from chaotic objects
such as distant stars, demonstrating the importance of two-photon
correlations and stimulating the development of modern quantum optics
(Nobel prize Roy Glauber, 2005). Advances in atom cooling and detection
have now allowed the observation of the atomic analogue of this Hanbury
Brown Twiss effect. In this presentation I will show how in Amsterdam we
managed to demonstrate the HBT effect with helium atoms, laser-cooled
and confined in a magnetic trap at temperatures ~1 microKelvin: Helium-4
atoms (bosons) bunch together and Helium-3 atoms (fermions) 'antibunch',
all this in the absence of interactions between the atoms.