Particle Physics
(The subatomic particles)
Quantum physics studies the behavior of the
fundamental building blocks of the universe at a scale smaller than
atoms, when tiny particles act in strange ways that can only be
described with advanced mathematics.
A Nobel prize for being in two places at once !!
U.S. physicist David
Wineland and France's Serge Haroche share the 2012 Nobel Prize in
physics for doing what Wineland once described as a scientific parlour
trick.
A physicist at the National Institute of
Standards and Technology, part of the U.S. Commerce Department, Wineland
was cited for trapping electrically-charged atoms, or ions, and
controlling and measuring them with light particles, or photons.Haroche of the College de France did similar work.
Tue Oct 9, 2012
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Pictures of the 2012 Nobel Prize for Physics
laureates Serge Haroche (L) of France and David Wineland of the U.S. are
displayed on a screen during a news conference at the Royal Swedish
Academy of Science in Stockholm, October 9, 2012.
Credit: Reuters/Bertil Enevag Ericson/Scanpix
|
Door to a new era: The Nobel Laureates have opened the door to a new era of experimentation with quantum physics
by demonstrating the direct observation of individual quantum particles
without destroying them. For single particles of light or matter the
laws of classical physics cease to apply and quantum physics takes over.
But single particles are not easily isolated from their surrounding
environment and they lose their mysterious quantum properties as soon as
they interact with the outside world. Thus many seemingly bizarre
phenomena predicted by quantum physics could not be directly observed,
and researchers could only carry out thought experiments that might in
principle manifest these bizarre phenomena.
Through their ingenious laboratory methods Haroche and Wineland together
with their research groups have managed to measure and control very
fragile quantum states, which were previously thought inaccessible for
direct observation. The new methods allow them to examine, control and
count the particles.
Observations: "Single particles are not easily isolated from
their surrounding environment, and they lose their mysterious quantum
properties as soon as they interact with the outside world," the Nobel
committee explained.
"Through
their ingenious laboratory methods Haroche and Wineland, together with
their research groups, have managed to measure and control very fragile
quantum states, which were previously thought inaccessible for direct
observation. The new methods allow them to examine, control and count
the particles."
Both scientists
work in the field of quantum optics, studying the fundamental
interactions between light and matter. The Nobel committee said they
used opposite approaches to the same problem: Wineland uses light
particles - or photons - to measure and control particles of matter -
electrons - while Haroche uses electrons to control and measure photons.
In the quantum world discovered by Niels Bohr,
Erwin Schroedinger and other giants of early 20th-century physics, tiny
objects such as electrons can be in two places at once, and can behave
as a particle one moment and as a wave the next, depending on how an
observer tries to measure it.In other words, the mere act of observation determines which form they take and even what reality is.Superposition was supposed to exist only in a quantum world inaccessible to real-world experiments.
Wineland
achieved it in the lab. When he hit the atom with half of the light
needed to move it, it was simultaneously immobile and in motion, until
eventually it was in two locations, 80 nanometers (billionths of a
meter) apart, at the same time.
# In one of the strange properties of quantum
mechanics, tiny particles act as if they are simultaneously in two
locations, based on the likelihood that they would be found at either,
known as a "superposition".
A quantum computer for your desk, much less
your mobile phone, is still many years away: in Wineland's laboratory in
Boulder, Colorado, electrically charged atoms or ions are kept inside a
trap by surrounding them with electric fields. The particles are
isolated from the heat and radiation in their environment by performing
the experiments in vacuum at extremely low temperatures.
But some of the materials needed to build quantum devices have already been synthesized.
Some
companies, like MagiQ in the U.S. and Swiss firm ID Quantique, are
already selling quantum cryptography equipment that allows unhackable
communication using the same fundamental theory.
# In a normal computer, a switch must either be
on or off. A quantum computer would work with switches that, like the
particles in Wineland's experiment, behaved as if they were in more than
one position at the same time.
An
example is a computer trying to work out the shortest route around town
for a travelling salesman. A traditional computer might try every
possible route and then choose the shortest. A quantum computer could do
the calculation in one step, as if the salesman travelled each route
simultaneously.
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