EVENTS, ADVANCES, AND NEWS
■ BY JEFF ECKERT
LASERS WITH CURVES filaments and plasma channels over
long enough distances for real-life
applications. It was ruefully noted that
“the practical use of laser filaments
may be years away, because the pulse
shape is not predictable, and that
makes control, which is much needed,
impossible.” But research continues.
PHOTO COURTESY OF DR.
CENTER FOR RESEARCH
AND EDUCATION IN OP TICS
AND LASERS, UNIVERSI TY
OF CENTRAL FLORIDA.
■ An ideal
Backed by the Air Force Office of Scientific Research (www.
ongoing effort is underway at the
University of Arizona’s College of
Optical Sciences and the Arizona
Center for Mathematical Sciences to
create curved laser beams that can
be used to detect explosives and
chemical/biological agents in remote
locations. The research is based on
Airy beams, a strange type of optical
wave that resists diffraction over long
distances and can accelerate freely
Prof. Demetrios Christodoulides,
of the University of Central Florida,
has explained the bending process.
“[The beams] are made up of a
combination of waves, one leading
one, which carries most of the beam’s
intensity and many smaller trailing
waves. These waves interfere with
each other so that the leading wave
curves one way while the tail bends in
the opposite direction.”
Apparently, such beams are
“self-healing” in that they can
easily reassemble themselves after
being blocked or distorted in the
atmosphere, which would make them
useful for passing through turbulence
and fog. Unfortunately, physicists
still need to come up with ways to
extend the laser-generated light
12 August 2009
PHOTO COURTESY OF NIST.
crystal, similar to arrays of qubits
fabricated using semiconducting and
superconducting circuitry. The NIST
team then applied customized
sequences of microwave pulses to
simultaneously reverse error
accumulation in all of the qubits. It
was observed, “simulations show that,
under appropriate conditions, this
method can reduce the error rate in
quantum computing systems up to a
hundred times more than comparable
The method is not entirely novel,
being an adaptation of “spin echo”
techniques used for decades to
suppress errors in nuclear magnetic
resonance. But we won’t tell anyone.
■ Crystal consisting of about 300 ions
spaced 10 m apart and fluorescing.
If you’ve been experiencing data errors with your quantum computer
(and who hasn’t?), you’ll be relieved
to know that the National Institute
of Standards and Technology (NIST,
www.nist.gov) has demonstrated a
technique for suppressing them.
The method counteracts the vulnerability of quantum memories
to be disrupted by stray electromagnetic fields, which can show
up as random errors in the
quantum bits (qubits).
The demonstration involved
an array of about 1,000 ultracold
beryllium ions trapped by electric
and magnetic fields with each ion
acting as a qubit of storage. The
ions formed a neatly ordered
It seems that the PC industry has omehow failed to adequately
address the surfing needs of 6- to
12-year-olds, but never fear, because
Disney Consumer Products (www.
ASUS Computer International (www.
asus.com) have collaborated to
develop the Disney Netpal netbook.
■ The Disney/ASUS Netpal netbook.
PHOTO COURTESY OF DISNEY CONSUMER PRODUC TS.