Atoms make quantum coprocessor

Researchers from Brussels Free University in Belgium (ULB) and the Niels Bohr Institute in Denmark have shown that the collective spin of clouds of atoms can be used to compute.

Atomic particles like atoms, electrons and photons have spin states that can be likened to the two poles of a magnet and can be used to represent the 1s and 0s of digital information. In addition, the weird quantum traits of superposition and entanglement make it possible to carry out many calculations at once on a series of spin states, making quantum computers potentially very powerful.

The trick is controlling and reading such states. This is easier using a cloud of atoms rather than a single atom or particle.

The researchers' previously proved that clouds of atoms could be entangled. Their new scheme theoretically generates a cloud of atoms whose collective spin points in two slightly different directions at once; this spin is relatively long-lived, making for plenty of time to carry out computations.

Most quantum computing schemes call for manipulating the quantum states of individual particles; there are several schemes, however, that could use atom clouds instead.

The researchers' method could also be used to strengthen the entanglement between distant entangled atom clouds used for quantum communications, according to the researchers.

The method could be ready for practical use within a decade, according to the researchers. The work appeared in the August 8, 2003 issue of Physical Review Letters.