superatomic circus

Pick of the pics and Updating Einstein’s Universe & Magic Universe

Seeing the superatomic circus

When ultra-cold rubidium atoms club together in the superatoms called Bose-Einstein condensates, they usually make untidy crowds, as on the left. But a team led by Stefan Kuhr and Immanuel Bloch at the Max-Planck-Institut für Quantenoptik in Garching, Germany, brings them to order in a neater pattern, as seen in the middle picture. With more rubidium atoms the superatom grows wider (right). Criss-cross laser beams create a lattice-like pattern of pools of light where the atoms like to congregate. When the laser light’s electric field is relatively weak, the atoms jump (by quantum tunnelling) from one pool to another, creating the usual disorder. A stronger field, as in the central and right-hand images, fixes them in the novel state of matter called a Mott insulator. But atoms can be lost from the condensate, which explains the ring-like appearance on the right. Images from MPQ.

[You’re recommended to click on the images for a better view]

Single atoms are located at the sites indicated by circles. Fig. 3 in Nature paper, Sherson et al. see ref.

What’s new here, in an advance online publication in Nature,  is not the creation of these kinds of  superatoms but the German team’s success in imaging them, with a specially developed microscope that picks up fluorescence from the atoms caused by the cooling process. In the image on the right individual atoms are pinpointed.

It’s exciting stuff, because we’re probably seeing the dawn of a new technology – after electronics comes “atomics”. If individual atoms in a superatom can be manipulated, they might be used to carry “addressable” information in an atomic computer.