Tuesday, Jun. 08, 2004

The Quantum Leaper

Nicolas Gisin
Though the technology appears to straddle the line between science and science fiction, the era of quantum teleportation has arrived. It's not the Star Trek-style beaming up of entire landing parties; the process operates at the subatomic level. What does that mean? Quantum teleportation, in short, is the transmission of characteristics — that is, the quantum state of a particular photon, or particle of light — from one place to another. While it falls short of a capability to beam people or objects to remote locations, it's much more than just sending a fax. The original is destroyed, but every one of its distinguishing features is re-created elsewhere. Researchers believe quantum teleportation will someday translate into many breakthrough applications ranging from uncrackable encryption methods to quantum computers that will run billions of times faster than today's fastest machines.

The concept of quantum teleportation, first postulated in 1993 by IBM researcher Charles Bennet, has been likened to voodoo. But it is a reality, due in large part to the work of Nicolas Gisin, 52, and his 20 or so graduate students and research assistants at the University of Geneva's Group of Applied Physics. In the basement of the university's old medical-school building, Gisin commands a series of laboratories crisscrossed with laser beams and crowded with the gizmos that make teleportation possible: photon counters, interferometers and plain old mirrors that bounce the lasers around. Last year Gisin was able to teleport a photon over four miles.

For now, the idea that anything bigger than a photon can be teleported is fantasy. "It is beyond any foreseeable technology to teleport a physical object like a pen, much less a person," says Gisin. He doesn't rule out, in the far future, the teleportation of a molecule. In the immediate future, there are other applications: last year, for example, a spin-off company of Gisin's lab called ID Quantique developed a quantum key that allows for communication — say, transactions between banks — that is completely inoculated against code-breaking attacks. Because the information is being transported in an unconventional way, it's impossible to track. The technology is being considered by the Geneva canton government for use in e-voting and other programs. "This is the way of the future," says Gisin, "and we can't afford not to be part of it."

Reported by Helena Bachmann/Geneva