Colorized
micrograph of a NIST single-photon detector made of
superconducting
nanowires patterned on molybdenum silicide.
Photo Credit:
Verma/NIST
(January 5, 2015) Detecting
individual particles of light just got a bit more precise—by 74 picoseconds to
be exact—thanks to advances in materials by National Institute of Standards and
Technology (NIST) researchers and their colleagues in fabricating
superconducting nanowires.
Although 74 picoseconds may not sound like much—a picosecond
is a trillionth of a second—it is a big deal in the quantum world, where light
particles, or photons, can carry valuable information. In this case it means
that much less “jitter,” or uncertainty in the arrival time of a photon. Less
jitter means that photons can be spaced more closely together but still be
correctly detected. This enables communications at a higher bit rate, with more
information transmitted in the same period.
Every little bit helps when trying to receive faint signals
reliably. It helped, for example, in NIST’s recent quantum teleportation record
and difficult tests of physics theories. In such experiments, researchers want
to decode as much information as possible from the quantum properties of
billions of photons, or determine if “entangled” photons have properties that
are linked before—or only after—being measured.