Theoretical and Experimental Techniques Used to Explore Many-Body Physics in Cold Atoms, Especially Optical Lattices

The first stage of producing an ultracold atomic gas is to vaporize a solid (with an “oven” or other source) to create a hot gas, whose center of mass is then slowed sufficiently to be trapped. The slowing is frequently accomplished by a “Zeeman slower”: a series of current carrying coils that generate magnetic fields, and which decrease in intensity over the length of the slower, to create a magnetic field gradient. Atoms used in this technique possess an electron spin degree of freedom so that the internal energy of the atom depends on the applied magnetic field and thus the magnetic field gradient introduces a potential energy gradient that slows the atoms.