Researchers at the Cavendish Laboratory have succeeded in trapping single atoms.

Researchers at the Cavendish Laboratory have succeeded in trapping single atoms. Single trapped atomic ions constitute the world's best controllable quantum systems. They are employed for modern quantum computers and for exploring the foundations of quantum mechanics.

The researchers store and confine single atomic ions in a radio-frequency trap originally invented by Wolfgang Paul (Nobel laureate 1989). After trapping, the ions are cooled using ultraviolet laser light. The laser light is derived from a sophisticated laser system specially developed for this purpose at the Cavendish Lab. Laser cooling lowers the temperature of the ions to less than a thousandth degree above absolute zero temperature. Upon reaching these extremely low temperatures the trapped ions condense into a very regular crystalline structure. In such a Coulomb crystal (see image) the spacing between the individual ions is on the order of 10 micrometers. Individual ions in the lattice can thus be well resolved with a microscope. More importantly even, the ions can be addressed and manipulated individually using tightly focused laser beams. This provides a promising avenue for quantum computation with many qubits.

Further information on this can be obtained from the Quantum Optics and Cold Atoms group.