Credit: K.
Irvine/NIST
(September 22, 2015) Researchers
at the National Institute of Standards and Technology (NIST) have “teleported”
or transferred quantum information carried in light particles over 100
kilometers (km) of optical fiber, four times farther than the previous record.
The experiment confirmed that quantum communication is
feasible over long distances in fiber. Other research groups have teleported
quantum information over longer distances in free space, but the ability to do
so over conventional fiber-optic lines offers more flexibility for network
design.
Not to be confused with Star Trek’s fictional “beaming up”
of people, quantum teleportation involves the transfer, or remote
reconstruction, of information encoded in quantum states of matter or light.
Teleportation is useful in both quantum communications and quantum computing,
which offer prospects for novel capabilities such as unbreakable encryption and
advanced code-breaking, respectively. The basic method for quantum
teleportation was first proposed more than 20 years ago and has been performed
by a number of research groups, including one at NIST using atoms in 2004.
The new record, described in Optica,* involved the transfer
of quantum information contained in one photon—its specific time slot in a
sequence—to another photon transmitted over 102 km of spooled fiber in a NIST
laboratory in Colorado.
The lead author, Hiroki Takesue, was a NIST guest researcher
from NTT Corp. in Japan. The achievement was made possible by advanced
single-photon detectors designed and made at NIST.