Mason Inman - science journalist

17 June 2007, for New Scientist

A device that can hold hundreds of atoms in a 3D array, and image each one individually, has been developed by scientists in the US.

The machine is an important stepping stone towards the development of a quantum computer, they say.

Many teams are looking for ways to build quantum computers, which process data using quantum particles such as photons, electrons and atoms.

Each particle carries a single bit of quantum information, or qubit, and the strange laws of quantum mechanics can be used to perform calculations at vastly greater speeds than are possible on conventional computers.

But to scale up these systems so that they can do meaningful calculations, researchers are looking for ways of trapping large numbers of particles and addressing them individually.

3D array

David Weiss, Karl Nelson, and Xiao Li at the Pennsylvania State University have taken a significant step in that direction by trapping atoms in an optical lattice – an interference pattern created when two laser beams meet.

The atoms become trapped between the light and dark fringes in the pattern, like ping pong balls in an egg box. In the past, researchers have used optical lattices to trap millions of atoms. "The difference in what we're doing in this apparatus is that we have a large array where we can observe each individual atom," Weiss says. Until now, the only lattices where individual atoms were visible were one-or two-dimensional arrays, and contained only a handful of atoms....

Read the rest of the article on the New Scientist website.