And the Winner Is ....

 An article on the 2012 physics Nobel Prize, written for 12-13 year olds...

 
Who won? Serge Haroche and David Wineland for “ ground-breaking experimental
methods that enable measuring and manipulation of individual quantum
systems.

What does that mean? When you go down to very small distances, you see
matter in the form of atoms. Similarly light also is made up of particles
called photons. These are not “classical” particles like a ball or a book,
but they are “quantum” particles. They have some very strange properties
that make it very, very difficult to isolate them and measure their physical
properties like momentum or position, energy or angular momentum.


In Wineland’s lab, using electric fields, ions were trapped in a small area
and then excited using laser pulses. It is a great feat to isolate
individual atoms and to put them in specific quantum mechanical states.


Haroche and coworkers trapped photons in a cavity made of special reflecting mirrors and then by sending in specially prepared ions one by one into the cavity, inferred the presence or absence of photons there and measured their quantum state.


Why does it matter? You may have heard about atomic clocks. They are a way
of measuring time using the oscillations of a caesium atom. Now you can have an optical clock which consists of just one ion or two ions in a trap. One ion’s oscillations are used to keep time, and the other ion is used to read the first one without destroying its quantum state. These clocks will be a hundred times more accurate than the caesium atomic clocks.


Another application is in building quantum computers.  Classical computers
work on binary logic, that is, their basic building blocks are bits that can
exist as 0 or 1. Now you have a quantum system that can be in a mixture of
states, a 0 and a 1 at the same time. A basic logic operation has been
demonstrated with these quantum particles and so we may have quantum
computers that work on quantum bits or q-bits in the future.
Complicated? But then who ever said getting the Nobel prize was easy?