“Creating Artificial Magnetic Fields to Act on Neutral Atoms”
Cold, quantum degenerate gases of neutral atoms have proved to be useful in simulating the behavior of quantum systems like electrons in solids. For example, cold atoms moving in optical lattices (periodic potentials created by interfering laser beams) show phenomena that are difficult to see in real solids. Neutral atoms, however, suffer from being neutral. For example, neutral atoms cannot straightforwardly simulate the behavior of charged particles experiencing a Lorentz force as they move in a magnetic field. We have used Raman coupling between spin states of atoms in their electronic ground state to create an artificial magnetic vector potential. Appropriate spatial dependence of this vector potential results in a synthetic magnetic field. We have studied the effects of such fields on atoms in a Bose-Einstein condensate and have observed other interesting effects arising from this kind of Raman coupling.