Switching device enables ultrafast quantum Internet

March 23, 2011

Researchers have developed a new switching device that can route quantum bits at very high speeds along a shared network of fiber-optic cable without losing the embedded entanglement information, says Prem Kumar, AT&T Professor of Information Technology at Northwestern University.

The researchers used pairs of polarization-entangled photons emitted into standard telecom-grade fiber. One photon of the pair was transmitted through the all-optical switch. Using single-photon detectors, the researchers found that the quantum state of the pair of photons was not disturbed; the encoded entanglement information was intact.

The device would enable a common transport mechanism, such as the ubiquitous fiber-optic infrastructure, to be shared among many users. Such a system could route a quantum bit, such as a photon, to its final destination just like an e-mail is routed across the Internet today.

Their work appears in the journal Physical Review Letters.