Atom Put in Superposition Microns ApartCategory: Science & Technology
Posted: June 7, 2012 10:46AM
Superposition has been mentioned a few times before in my news items, normally with respect to a particle having multiple spin states, which will be needed for quantum computing. Superposition allows for more than just multiple spin states though, but actual separate positions in space, which is what researchers at the University of Bonn have achieved with a cesium atom.
The first step was to cool the atom below a millionth of a degree above absolute zero using lasers that also hold the atom. Quantum mechanical effects are easily disrupted by energy, so this extremely low temperature is needed. Next the atom was put into a spin-state superposition, because the direction the atom moves because of the laser is determined by the spin. Superposition begets superposition so the atom traveled in both directions for the two different spin states. Ultimately the atom was separated by ten microns, which is an almost unbelievable distance when considering that an atom's diameter is measured in nanometers or angstroms, which are 1000-10,000 times smaller.
The researchers intend to develop this for simulating complex quantum systems. When the atom is in its superposition it is able to reach out and interact with the adjacent atoms. The adjacent atoms then have information about the atom in superposition, and that atom retains information about its neighbors, even after the superposition collapses. This creates a kind of atomic network which could be utilized like computer memory and allow for the simulation and control of real systems.