Photonics Spectra - March 2009

Teleporting a step closer
to quantum computing

COLLEGE PARK, Md. – It’s not “Star Trek,” but it does seem like science fiction. Researchers from the Joint Quantum Institute at the University of Maryland have for the first time teleported information from one atom to another at a distance of 1 m, without the data passing through any physical medium. Because atoms can store quantum bits – or qubits – the technique could be used to hold and manage quantum data over long distances, something not feasible before.

“This is a new way to pipe around quantum information,” said physics professor and research team leader Christopher Monroe. Such long-distance quantum communication theoretically would be completely secure and immune to eavesdropping. Attempts at quantum communication are in their infancy, limited in part by short-range capabilities. Other uses of the new technique include multiparty communications in something akin to a quantum Internet or in quantum computing, which, because of its nature, can solve certain problems that classical computing cannot handle practically.

These applications are possible, in part, because a qubit,

unlike a classical bit, is a superposition of two or more states. A qubit remains in this combination of yes and no until a measurement is made.

In demonstrating its scheme, Moore’s team used two ytterbium ions, holding them in unconnected vacuum traps sepa-

For the first time, researchers have
stored information in one trapped atom
(below), then teleported it across a
distance of 1 m (diagrammed on right;
setup shown on next page) to a different atom.
Images courtesy of Curt Suplee, Joint Quantum
Institute and the University of Maryland.