arXiv:1101.4785 · Physical Review A
Loading of bosons in optical lattices into the p band
Jonas Larson, J.-P. Martikainen
Abstract
We present a method for transferring bosonic atoms residing on the lowest $s$ band of an optical lattice to the first excited $p$ bands. Our idea hinges on resonant tunneling between adjacent sites of accelerated lattices. The acceleration effectively shifts the quasibound energies on each site such that the system can be cast into a Wannier-Stark ladder problem. By adjusting the acceleration constant, a situation of resonant tunneling between the $s$ and $p$ bands is achievable. Within a mean-field model, considering ${}^{87}$Rb atoms, we demonstrate population transfer from the $s$ to the $p$ bands with around 95$%$ efficiency. Nonlinear effects deriving from atom-atom interactions, as well as coupling of the quasibound Wannier-Stark states to the energy continuum, are considered.