repeater, extending the distance covered
by quantum networks. Today, the lack of
such a device restricts quantum communication to, at most, approximately 100 km
Another likely necessity will be the
integration of many devices into a small
volume, something difficult to do with
current sources. Work done by Toshiba
Research Europe with electrically driven
quantum-dot LEDs points the way toward
Making More Money in the Meantime
While working on quantum communication, companies have turned elsewhere for
additional revenues. A case in point
comes from Geneva’s ID Quantique
SA. As with others, its implementation of quantum key distribution
requires a random number generator
as the basis for cryptography.
The company achieves this by
generating, then detecting, a single
visible photon in a secure enclosure.
A matchbox-size component converts
quantum-derived random fluctuations into a string of 1’s and 0’s.
Because the device can be mounted
on a card in a computer or server,
the technology has found a home
in many applications far removed
from quantum communication.
“Our largest market for this prod-
uct is the online gaming market,
where they need randomness. They
need good randomness, for example,
to draw winning numbers or to shuf-
fle card decks,” said ID Quantique
CEO Grégoire Ribordy.
A quantum key distribution system can function
as a single-photon interferometer (right), creating a
passive fiber sensor for harsh, borehole environments (above). Courtesy of MagiQ Technologies.