Dimerized Mott insulators in hexagonal optical lattices

7 April 2014

Photo: AG Sengstock

We study bosonic atoms in optical honeycomb lattices with anisotropic tunneling and find dimerized Mott insulator phases with fractional filling. These incompressible insulating phases are characterized by an interactiondriven localization of particles in respect to the individual dimers and large particle-number fluctuations within the dimers. We calculate the ground-state phase diagrams and the excitation spectra using an accurate cluster mean-field method. The cluster treatment enables us to probe the fundamental excitations of the dimerized Mott insulator allowing the distinction from normal Mott insulating phases.

New J. Phys. 16, 093023 (2014)

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