Phys. Rev. A doi:10.1103/PhysRevA.79.053823 (2009)

The original 'Poisson spot' experiment had a crucial role in proving the wave nature of light: because of the way that waves diffract, light shining at a circular object casts a bright spot in the centre of the object's shadow.

Thomas Reisinger of the University of Bergen in Norway and his colleagues now demonstrate that a beam of deuterium molecules can also create a Poisson spot — replicating the classical experiment using neutral matter waves.

The authors suggest several potential applications, ranging from 'printing' larger molecules precisely on a surface to the study of quantum decoherence and other effects at the boundary of quantum and classical physics. Unlike other diffraction methods, Poisson's spot is wavelength independent.