University of Calgary

Quantum light

Februay 16, 2010

Physicists play Lego with photons

Co-authors Andrew MacRae (left), a  PhD physics student, and Alexander Lvovsky, a professor in the Department of Physics and Astronomy, adjust their laser array. / Photo: Ken Bendiktsen
While many of us as kids enjoyed constructing little houses out of toy bricks, this task is much more difficult if the bricks are elementary particles. It is even harder if these are particles of light—photons—which can only exist while flying at an incredible speed and vanish if they touch anything.

Yet a team at the University of Calgary has accomplished exactly that. By manipulating a mysterious quantum property of light known as entanglement, they are able to mount up to two photons on top of one another to construct a variety of quantum states of light—that is, build two-story quantum toy houses of any style and architecture.

The results of their research were published on Nature Photonics’ website on Sunday.

“This ability to prepare or control complex quantum objects is considered the Holy Grail of quantum science,” says Andrew MacRae, a co-author of the paper and PhD physics student. “It brings us closer to the onset of the new era of quantum information technology.”

This new generation of technology is expected to endow us with qualitatively new capabilities. This includes measurement instruments of extraordinary sensitivity, dramatically faster computers, secure communication systems and enhanced control over chemical reactions.

“Light is a particularly interesting quantum object because it’s an excellent communication tool,” says paper co-author Alexander Lvovsky, a professor in the Department of Physics and Astronomy. “No matter what future quantum computers will be made of, they’ll talk to each other using photons.”

A copy of “Quantum-optical state engineering up to the two-photon level,” by Alex Lvovsky, Andrew MacRae, Erwan Bimbard and Nitin Jain can be found on Nature Photonics:


Bookmark and Share