Feb.
24, 2005
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Circuits
Mimic Atom Pairs in Quantum Computing Advance
|
NIST
physicist Ray Simmonds holds a protective box containing
“artificial atoms” that might be used in quantum
computers. Next to him is a cryogenic refrigerator that
cools the box to temperatures near absolute zero.
© Geoffrey Wheeler
For a high-resolution version of this image, contact Gail
Porter. |
Two
superconducting devices have been coaxed into a special, interdependent
state that mimics the unusual interactions sometimes seen in
pairs of atoms, according to a team of physicists at the National
Institute of Standards and Technology (NIST) and University
of California, Santa Barbara (UCSB). The experiments, performed
at the NIST laboratory in Boulder, Colo., are an important step
toward the possible use of “artificial atoms” made
with superconducting materials for storing and processing data
in an ultra-powerful quantum computer of the future.
The work,
reported in the Feb. 25 issue of the journal Science*,
demonstrates that it is possible to measure the quantum properties
of two interconnected artificial atoms at virtually the same
time. Until now, superconducting qubits—quantum counterparts
of the 1s and 0s used in today’s computers—have
been measured one at a time to avoid unwanted effects on neighboring
qubits. The advance shows that the properties of artificial
atoms can be coordinated in a way that is consistent with a
quantum phenomenon called “entanglement” observed
in real atoms. Entanglement is the “quantum magic”
allowing the construction of logic gates in a quantum computer,
a means of ensuring that the value of one qubit can be determined
by the value of another in a predictable way.
The advance opens
the door to performing simple logic operations using artificial
atoms, an important step toward possibly building superconducting
quantum computers.
"Whether
or not quantum computing becomes practical, this work is producing
new ways to design, control and measure the quantum world of
electrical systems,” says Ray Simmonds, a NIST physicist
and a co-author of the Science paper. “We have
already detected previously unknown, individual nanoscale quantum
systems that have never before been directly observed, a discovery
that may lead to unanticipated advances in nanotechnology.”
For further
information, see www.nist.gov/public_affairs/releases/qubits.htm.
*R. McDermott,
R.W. Simmonds, M. Steffen, K.B. Cooper, K. Cicak, K. Osborn,
S. Oh, D.P. Pappas, and J.M. Martinis, “Simultaneous state
measurement of coupled Josephson phase qubits,” Science,
Feb. 25, 2005.
Nano-sized
Chip Features Measured with Atom 'Ruler'
|
This
colorized graphic shows a cross section of the new
NIST atom-based "ruler." Included are six
silicon features ranging in width from 40 nm to 275
nm.
Click
on graphic to open high resolution version.
Photo credit: Accurel/Courtesy NIST |
Device
features on computer chips as small as 40 nanometers (nm)
wide—less than one-thousandth the width of a human
hair—now can
be measured reliably thanks to new test structures
developed by a team of physicists, engineers, and statisticians
at the National Institute of Standards and Technology (NIST),
SEMATECH and other collaborators. The test structures are
replicated on reference materials that will allow better
calibration of tools that monitor the manufacturing of microprocessors
and similar integrated circuits.
|
The
large purple rectangle in this colorized image is
a chip feature about 40 by 150 nanometers in size,
surrounded by encapsulating material. The magnified
section shows the planes of silicon atoms used to
calibrate feature measurements.
Click
on graphic to open high resolution version.
Photo credit: Accurel/Courtesy NIST |
The
new test structures are the culmination of NIST’s
more than four-year effort to provide standard “rulers”
for measuring the narrowest linear features that can be
controllably etched into a chip. The NIST rulers are precisely
etched lines of crystalline silicon ranging in width from
40 nm to 275 nm. The spacing of atoms within the box-shaped
silicon crystals is used like hash marks on a ruler to measure
the dimensions of these test structures. Industry can use
these reference materials to calibrate tools to reliably
measure microprocessor-device gates, for example, which
control the flow of electrical charges in chips.
“We have
caught up to the semiconductor industry roadmap for linewidth
reference-material dimensions with this work,” says
Richard Allen, one of the NIST researchers involved in the
project. “With the semiconductor industry, one has
to run at full speed just to keep up.”
The new reference
materials, configured as a 9 millimeter (mm) by 11 mm chip
embedded in a silicon wafer, are now being evaluated by
SEMATECH member companies. Compared to a batch of prototype
test structures produced by NIST in 2001, the new reference
materials offer a wider range of reference feature sizes,
including some that are much narrower, and they are measured
much more precisely (with uncertainties of less than 2 nm
compared to 14 nm previously). In the absence of reference
materials such as these, companies have calibrated measurement
tools using in-house standards, which may neither be accurate
nor agree with each other.
The
new materials will be unveiled publicly at a workshop co-sponsored
by NIST and SEMATECH on March 2, in conjunction with a SPIE
(International Society for Optical Engineering) meeting
in San Jose, Calif.
For
further information, see www.nist.gov/public_affairs/releases/atom_rulers.htm.
NIST
Software To Guide Federal 'Buy Green' Drive
A
National Institute of Standards and Technology (NIST) analysis
and decision-making software program will play a key role
in selection of biobased products that qualify for a major
federal “green” preferential purchase program,
according to U.S. Department of Agriculture (USDA) rules published
in the Federal Register that became effective Feb.
10.
The USDA
guidelines begin a federal government program authorized by
the 2002 Farm Bill to require purchase of biobased products
containing renewable agricultural materials (including plant,
animal and marine material) or forestry materials. Within
one year, all federal agencies must create a biobased preferred
procurement program based on the USDA rules.
The USDA
will use NIST’s Building for Environmental and Economic
Sustainability (BEES) tool to evaluate the environmental and
economic performance of biobased products over their life
cycles. With support from the USDA Agricultural Research Service,
the USDA Office of the Chief Economist, and the U.S. Environmental
Protection Agency, NIST expanded the BEES program. The program
previously was primarily used to evaluate building products.
It now includes performance information for products made
from soybeans, corn, wheat, rice, cotton, canola, potatoes,
wool and other renewable materials.
As a
result, the new BEES program can analyze the environmental
and health impact of biobased greases, fuel additives, hydraulic
fluids, polymers, industrial solvents, fertilizers, cutting
oils and other biobased products. Impacts are evaluated at
each life-cycle stage including raw material acquisition,
manufacture, transportation, installation, use and waste management.
BEES also measures the life-cycle cost of biobased products
by considering the costs for purchase, installation, operation,
maintenance, repair, replacement and waste management.
USDA
will make BEES environmental and economic performance results
available to federal procurement officials when designating
product categories for preferred procurement. Once designated,
biobased products within those categories must be purchased
unless they are not readily available, do not perform as required,
or cost substantially more than comparable petroleum-based
alternatives. USDA is currently working on plans that will
enable manufacturers to apply for a “USDA Certified
Biobased Product Label” for their products. USDA will
require BEES analysis for products seeking the labels.
For more
information, visit http://www.bfrl.nist.gov/oae/software/bees_USDA.html.
New
NIST Reference Material Reinforces Fragile-X Screens
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NIST
researcher Kristy Richie analyses DNA samples as part
of a project to prepare new "Fragile X" reference
materials.
© Robert Rathe
For a high-resolution version of this image, contact Gail
Porter. |
A
new Standard Reference Material from the National
Institute of Standards and Technology (NIST) will help clinical
genetics labs improve the accuracy of their diagnostic tests
for the most common cause of hereditary mental retardation.
“Fragile
X Syndrome” is a genetic mutation affecting approximately
one in 3,600 males and one in 4,000 to 6,000 females. It has
been linked to several physical abnormalities and to intellectual
problems ranging from minor learning disabilities to severe
mental retardation and autism. The mutation is characterized
by an excessive number of repeats of a sequence of three nucleotides
(the chemical building blocks of DNA) within a particular
gene on the human X chromosome.
Proper
diagnosis depends critically on accurate counts of the number
of triplet repeats. Individuals with up to 44 repeats are
normal; individuals with 55 to 200 repeats fall into the premutation
category (unaffected, but the number of repeats can increase
in their children, who can then be affected); and those with
200 or more repeats have the full mutation and Fragile X syndrome.
To assist
clinical diagnostic and genetic testing laboratories in accurately
counting fragile-X repeat sequences, NIST has developed a
new reference material that can be used as a check on test
procedures and for quality control. SRM 2399, “Fragile
X Human DNA Triplet Repeat Standard” consists of nine
samples of DNA measured and certified by NIST for triplet
repeats ranging from 20 to 118. The triplet repeat standard
joins more than 50 reference materials produced by NIST for
quality control in clinical testing.
Media
Contact:
Michael
Baum, michael.baum@nist.gov,
(301) 975-2763
Protecting
Drinking Water Supplies Within Buildings
Mention
drinking water contamination and most people would suspect problems
with the ground water or with a water treatment plant. However,
contamination of a building’s internal piping or associated
household appliances, whether by terrorist act or through an
unintentional mishap, also could pose a serious threat to the
health of building occupants. Recently, the National Institute
of Standards and Technology (NIST) and the Environmental Protection
Agency's National Homeland Security Research Center (NHSRC)
joined forces to cut the risk of this little explored hazard.
Under an
interagency agreement, researchers from the two organizations
have launched an investigation of contamination possibilities
affecting internal water lines and appliances such as hot water
heaters, dishwashers and icemakers. NIST researchers will conduct
detailed measurements, analysis and modeling of the transport,
accumulation and removal of potential contaminants in building
plumbing systems. This work, which is scheduled for completion
in summer 2006, will provide the technical basis for EPA guidelines
for effective responses to contamination incidents.
NIST is
currently conducting laboratory measurements and modifying
its small and full-scale plumbing test facilities to duplicate
typical building piping systems. NIST and EPA scientists
will
use safe surrogates for possible biological and chemical contaminants
in the contamination and decontamination tests.
Media
Contact:
John
Blair, john.blair@nist.gov,
(301) 975-4261
1,000th
Baldrige Award Application Will Be Free
Since
1988, 999 applications have been submitted for the prestigious
Malcolm Baldrige National Quality Award, the nation’s
Presidential award for quality and organizational performance
excellence. To celebrate the arrival of the 1,000th application,
NIST will waive the fee for the organization submitting
the 1,000th application (the first application to be received
for the 2005 Baldrige Award). Application fees range from
$5,000 for large for-profit organizations to $500 for
non-profit education organizations. The deadline for applications
is May 26, 2005.
Applying
for the Baldrige Award is a cost-effective way to
gain
an outside perspective on an organization’s strengths
and opportunities for improvement. All organizations
that
apply receive from 300 to 1,000 hours of review by a
minimum of eight specially trained experts. Every applicant
receives
an extensive feedback report highlighting strengths and
areas to improve. “We applied for the award, not
with the idea of winning, but with the goal of receiving
the evaluation of the Baldrige examiners,” said
Bob Barnett, executive vice president, Motorola, Inc.
“That evaluation was comprehensive, professional
and insightful ... making it perhaps the most cost-effective,
value-added business consultation available anywhere
in
the world today,” he said. For more information
on the benefits of applying for the Baldrige Award,
see
http://baldrige.nist.gov/Why_Apply.htm.
While
relatively few organizations apply for the Baldrige
Award,
thousands more use the Baldrige performance excellence
criteria as a tool to assess their performance in areas
ranging from leadership to strategic planning and from
customer relationships to business results. Annually,
more than 500,000 copies of the criteria are downloaded
and more than 50,000 copies are mailed. The criteria,
application package and other material are available
free of charge by calling (301) 975-2036, or can be
downloaded
from the Web site at http://baldrige.nist.gov/index.html.
Media
Contact:
Jan
Kosko, janice.kosko@nist.gov,
(301) 975-2767
Quick
Links
Workshop
on Manufacturing R&D
A
one-day public forum on manufacturing research and
development will be held March 3, 2005, at the U.S.
Department of Commerce in Washington, D.C. Sponsored
by an interagency working group of the National Science
and Technology Council, the meeting will focus on
three priority technology areas: nanomanufacturing,
manufacturing for the hydrogen economy, and intelligent
and integrated manufacturing systems.
The
purpose of the meeting is to review the current state
of the art in the three focus areas and to collect
public comments on remaining challenges and gaps in
research. The Interagency Working Group of the Committee
on Technology will consider public comments presented
at the forum when it prepares its recommendations
for federal manufacturing R&D programs for the
next five to 10 years.
To view an agenda or register for the meeting, see http://www.ostp.gov/mfgiwg/.
Experts
Urge Redefinition of the Kilogram
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Shown
above is the U.S. National Prototype Kilogram,
which currently serves as the nation's primary
standard for measuring mass. It was assigned to
the United States in 1889 and is periodically
recertified and traceable to the primary international
standard, "The Kilogram," held at the
Bureau International des Poids et Mesures near
Paris.
© Robert Rathe
For a high-resolution version of this image, contact
Gail Porter.
|
It’s
time to replace the 115-year-old kilogram artifact
as the world's official standard for mass, even though
experiments generally thought necessary to achieve
this goal have not yet reached their targeted level
of precision. That's the conclusion of an upcoming Metrologia
journal article* authored by five eminent scientists
from the United States, United Kingdom and France
that was discussed at a scientific meeting of the
Royal Society of London on Feb. 14-15.
The
authors of this Metrologia paper suggest
replacing the kilogram artifact—a cylinder of
platinum-iridium alloy about the size of a plum—with
a definition based on one of two unchanging natural
phenomena, either a quantity of light or the mass
of a fixed number of atoms.
The
five authors, including three from the U.S. National
Institute of Standards and Technology (NIST), one
from the University of Reading in the United Kingdom,
and a former director of the Bureau International
des Poids et Mesures (BIPM) near Paris, conclude that
redefining the kilogram now in terms of an invariable
property of nature rather than a material object could
immediately have many benefits. For instance, it would
improve the precision of certain electrical measurements
50-fold and would enable physicists to make more precise
calculations in studying the fundamental quantum properties
of atoms and other basic particles. The paper outlines
how this could be accomplished without impairing the
current international system of mass measurements.
For
further information see www.nist.gov/public_affairs/newsfromnist_redef_kilogram.htm.
*
I.M. Mills, P.J. Mohr, T.J. Quinn, B. Taylor, E. Williams,
"Redefinition of the kilogram: A decision whose
time has come," Metrologia, expected
online publication, Feb. 2005.
Biometrics
Focus of Two NIST Workshops
Two
upcoming workshops at NIST will focus on biometrics, e-authentication
and fingerprint standards.
The
objective of a March 30-31 workshop will be to determine
how biometrics can be used to remotely verify the identity
of a person who wants to conduct business or communicate
with the government using the Internet. In addition to
NIST, the workshop is being sponsored by a wide variety
of interested
government organizations and others, including the Departments
of Defense and Homeland Security, the General Services
Administration
and the Biometric Consortium. Details and online registration
are available at http://www.nist.gov/public_affairs/confpage/050330.htm.
Co-sponsored
by the Federal Bureau of Investigation, the ANSI/NIST
Fingerprint
Standard Workshop, April 26-28, will review and update
a standard approved in 2000 for the electronic exchange
of
fingerprint images (Data Format for the Interchange of
Fingerprint, Facial & Scar Mark & Tattoo Information,
ANSI/NIST-ITL 1-2000). Details and online registration
are available at
http://www.nist.gov/public_affairs/confpage/050426.htm.
(Return
to NIST News Page)
Editor:
Gail Porter
Date
created:2/24/05
Date updated:2/24/05
Contact: inquiries@nist.gov
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