3 research outputs found
Critical entropies for magnetic ordering in bosonic mixtures on a lattice
We perform a numeric study (worm algorithm Monte Carlo simulations) of
ultracold two-component bosons in two- and three-dimensional optical lattices.
At strong enough interactions and low enough temperatures the system features
magnetic ordering. We compute critical temperatures and entropies for the
disappearance of the Ising antiferromagnetic and the xy-ferromagnetic order and
find that the largest possible entropies per particle are ~0.5kB. We also
estimate (optimistically) the experimental hold times required to reach
equilibrium magnetic states to be on a scale of seconds. Low critical entropies
and long hold times render the experimental observations of magnetic phases
challenging and call for increased control over heating sources.Comment: 6 pages, 6 figure
Quantum magnetism and counterflow supersolidity of up-down bosonic dipoles
We study a gas of dipolar Bosons confined in a two-dimensional optical
lattice. Dipoles are considered to point freely in both up and down directions
perpendicular to the lattice plane. This results in a nearest neighbor
repulsive (attractive) interaction for aligned (anti-aligned) dipoles. We find
regions of parameters where the ground state of the system exhibits insulating
phases with ferromagnetic or anti-ferromagnetic ordering, as well as with
rational values of the average magnetization. Evidence for the existence of a
novel counterflow supersolid quantum phase is also presented.Comment: 8 pages, 6 figure