Creating fractional quantum Hall states with atomic clusters using   light-assisted insertion of angular momentum
  We describe a protocol to prepare clusters of ultracold bosonic atoms in strongly-interacting states reminiscent of fractional quantum Hall states. Our scheme consists in injecting a controlled amount of angular momentum to an atomic gas using Raman transitions carrying orbital angular momentum. By injecting one unit of angular momentum per atom, one realizes a single-vortex state, which is well described by mean field theory for large enough particle numbers. We also present schemes to realize fractional quantum Hall states, namely the bosonic Laughlin and Moore-Read states. We investigate the requirements for adiabatic nucleation of a such topological states, in particular comparing linear Landau-Zener ramps and arbitrary ramps obtained from optimized control methods. We also show that this protocol requires excellent control over the isotropic character of the trapping potential. 
Junyi Zhang, J\'er\^ome Beugnon, Sylvain Nascimbene
cond-mat.quant-gas