Quantum World 2012

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.

The 2012 Nobel Prize in Physics was awarded jointly to Serge Haroche and David J. Wineland "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems".

 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

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.