Description
We have observed vortex nucleation in a rotating optical
lattice. A Bose-Einstein condensate, of Rb-87 atoms, was
loaded into a static two-dimensional lattice and the
rotation frequency of the lattice was then increased from
zero. We have studied how vortex nucleation depends on the
optical lattice depth and rotation frequency. For deep
lattices above the chemical potential of the condensate we
observed a linear dependence of the number of vortices
created with the rotation frequency, even below the
thermodynamic critical frequency required for vortex
nucleation. At these lattice depths the system formed an
array of Josephson-coupled condensates. The effective
magnetic field produced by rotation introduced
characteristic relative phases between neighbouring
condensates, such that vortices were observed upon ramping
down the lattice depth and recombining the condensates.
Future work towards direct quantum simulation (DQS) of
frustrated antiferromagnets, and the observation of strongly
correlated states of bosons analogous to those of electrons
in the Fractional Quantum Hall Efffect will also bediscussed.
Primary author
Prof.
Chris Foot
(University of Oxford)
