arXiv:0907.0423 · Europhysics Letters (EPL)
Frustrated quantum antiferromagnetism with ultracold bosons in a triangular lattice
André Eckardt, Philipp Hauke, Parvis Soltan-Panahi, C. Becker, K. Sengstock, Maciej Lewenstein
Abstract
We propose to realize the anisotropic triangular-lattice Bose-Hubbard model with positive tunneling matrix elements by using ultracold atoms in an optical lattice dressed by a fast lattice oscillation. This model exhibits frustrated antiferromagnetism at experimentally feasible temperatures; it interpolates between a classical rotor model for weak interaction, and a quantum spin-1/2 $XY$-model in the limit of hard-core bosons. This allows to explore experimentally gapped spin liquid phases predicted recently [Schmied et al., New J. Phys. {\bf 10}, 045017 (2008)].