PHYS598MAP Spring 2005 Blog

1. The AMO secret handshake — what AMO physicists really mean by polarization. We talk about light having three polarizations: right-circular, left-circular, and pi.

2. To calculate how light really couples ground and excited electronic states, we have to calculate matrix elements of r. There is a big long formula for working out the angular-momentum part of that matrix element, but most AMO people use handy charts. The reduced matrix element for r must be measured, and is on the order of ea₀.

3. So-called "lin perp lin" lattices work because when light is far detuned from a resonance (but not too far compared with the fine structure), the potential experienced by atoms is polarization-dependent (it's also state-dependent).

4. We can see clean, direct Rabi oscillations between ground and excited states (without spontaneous emission) if we use a "forbidden" transition. We saw an example in ⁴⁰Ca⁺.

Matt White made a comment about electric quadrupole transitions being possible in our semi-classical picture if we expand the operator:

to higher order. I think that he is basically right. But, expanding that operator to higher order (or just not expanding it at all, which gives you recoil) is basically admitting to photons. We'll see that this operator is intimately connected to the idea of a photon.

Cheers,

Brian