Electrons coaxed into planet-like orbits

[bascule]

http://www.sciencedaily.com/releases/2008/06/080630173921.htm

 

I don't even want to try to regurgitate this, but ScienceDaily is trumpeting claims of millimeter-sized atoms through some crazy laser excitation thing. In this state the electrons start to have classical instead of quantum properties and all start orbiting the electron like a planet.

 

All I gotta say is... fo real?

[Mr Skeptic]

I gotta say is, for how long? Those orbits would be extremely unstable.

[swansont]

Rydberg states with maximal angular momentum, which gives you the most circular orbitals. hence they are known a s circular Rydberg states. Very close to the ionization threshold, which makes it hard to do, and they are easily ionized, but IIRC they are longer-lived than you might expect. Normally, highly-excited atoms decay quickly, but here you have to decay one level at a time to get rid of all of the angular momentum: l= n-1 and m= ±l. Since these levels are really close together, and there's only one decay path, they have long lifetimes.

 

"Using lasers, the researchers excited potassium atoms to extremely high levels. Using a carefully tailored series of short electric pulses, the team was then able to coax the atoms into a precise configuration with one point-like, "localized" electron orbiting far from the nucleus"

 

You use the lasers you have that you can tune, and the short electric pulses are what get you between the different values of l. Often you'll use circularly polarized microwaves and increase l and m at the same time. And this is the closest the Bohr model gets to being correct in its atomic description.