The new theory could lead to faster and smaller electronic components, for which quantum tunneling is a significant factor. It will also lead to a better
understanding of diverse areas such as electron microscopy, nuclear fusion and
DNA mutations.
"Timescales this short have never been explored before. It's an entirely new world," said Professor Anatoli Kheifets from The Australian National University
(ANU) who is a member of the international team.
At very small scales quantum physics shows that particles such as electrons have wave-like properties and their exact position is not well
defined nike air
presto uncaged solde , meaning that they can occasionally sneak through
apparently impenetrable barriers, a phenomenon called quantum tunneling.
Quantum tunneling plays a role in a number of phenomena, such as nuclear fusion in the sun, scanning tunneling microscopy and flash memory for computers.
However, the leakage of particles also limits the miniaturization of electronic
components.
Professor Kheifets and Dr. Igor Ivanov, from the ANU Research School of Physics and
Engineering nike
air presto homme solde , are members of a team which studied ultrafast
experiments at the attosecond scale (10-18 seconds), a field that has developed
in the past 15 years.
Until their work, a number of attosecond phenomena could not be adequately explained, such as the time delay when a photon ionised an atom.
"At that timescale the time an electron takes to quantum tunnel out of an atom was thought to be significant. But the mathematics says the time during
tunneling is imaginary, a complex number, which we realized meant it must be an
instantaneous
process nike air
presto rose solde ," said Professor Kheifets.
"A very interesting paradox arises, because electron velocity during tunneling may become greater than the speed of light. However, this does not
contradict the special theory of relativity, as the tunneling velocity is also
imaginary," said Dr Ivanov, who has took up a position at the Center for
Relativistic Laser Science in South Korea.
The team's calculations made using the Raijin supercomputer showed that the delay in photoionisation originates not from quantum tunneling but from the
electric field of the nucleus attracting the escaping electron.
The results provide an accurate calibration for future attosecond-scale research nike air
presto verte solde , said Professor Kheifets.
"It's a good reference point for future experiments, such as studying proteins unfolding, or speeding up electrons in microchips," he said.
The research is published in Nature Physics journal.
WASHINGTON, Feb. 11 (Xinhua) -- In her first testimony to the Congress, U.S. Federal Reserve Chair Janet Yellen reiterated central bank's plan to taper its
stimulus exit despite recent weakness in the economy.
The current economic situation and outlook nike air
presto bleu solde , as well as the monetary policy, were the main focus of
the hearing held twice a year.
Yellen told lawmakers she expected "a great deal of continuity" in the central bank's monetary policy, saying that she served on the Fed policy-setting
committee as the bank formulated its current policy strategy and she strongly
supported that strategy.
Yellen, 67, took the oath of office to lead the Federal Reserve System on Feb. 3, succeeding Ben
Bernanke nike air
presto rouge solde , who stepped down after eight turbulent years. She was
previously the Fed's vice Chair.
In the public debut in her new role, Yellen said while the economy gained steam at the end of 2013, recovery in the U.S. labor market was "far from
complete," underscoring the importance of considering more than just the
unemployment rate when evaluating the conditions of the labor market.
Her point of keeping an eye on wider range of labor indicators is particularly important as the unemployment rate, now at 6.6 percent, is near the
6.5 percent threshold the Fed once identified as the level that would need to be
reached before officials would consider a hike in the interest rates.
"If coming information broadly supports the Committee's expectation of ongoing improvement in labor market conditions and inflation moving back toward
its long-run
objective nike air
presto grise solde , the Committee will likely reduce the pace of asset
purchases in further measured steps at future meetings," Yellen indicated steady
pullback in Fed stimulus, referring to the Federal Open Market Committee, which
sets monetary policy.
While admitting she was "surprised" by the two recent jobs reports that showed the pace of job creation running under what she had expected, Yellen
cautioned against jumping to conclusions of the longer trend. She told the
Congress that the Fed needs to see a "notable change" in the economic outlook to
consider pausing its withdrawal of stimulus.
The Fed trimmed its monthly purchases of Treasury and mortgage- backed securities by a total of 10 billion dollars in both December and January, citing
strengthening economy and continued improvement in the labor market.
The Fed policymakers have suggested they would continue to reduce the bond buying nike air
presto noir solde , which now totals 65 billion dollars a month, at a
similar pace at each Fed meeting and end it by the end of 2014, provided the
economy develops generally in line with expectations.
Yellen also highlighted the Fed's financial regulatory role, saying that the work of making the financial system more robust " has not yet been completed."
GWANGJU, South Korea, July 14 (Xinhua) -- The 12-day 2015 Gwangju Summer Universiade concluded here on Tuesday and was praised as "a
big nike air
presto blanche solde , big success".
At the final press briefing, Claude-Louis Gallien, president of the International University Sports Federation (FISU), said that all the athletes
and coaches we. Cheap Manchester
City Jerseys Cheap Borussia
Dortmund Jerseys Cheap
Bayern Munich Jerseys Cheap
FC Barcelona Jerseys Cheap
Tottenham Hotspur FC
Jerseys Wholesale AS Roma
Jerseys Wholesale AC Milan
Jerseys Wholesale Texans
Jerseys Wholesale Baltimore
Ravens Jerseys Wholesale
Carolina Panthers Jerseys
