Issue
EPL
Volume 81, Number 1, January 2008
Article Number 10005
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/81/10005
Published online 27 November 2007
EPL, 81 (2008) 10005
DOI: 10.1209/0295-5075/81/10005

Characterization of topological states on a lattice with Chern number

M. Hafezi1, A. S. Sørensen2, M. D. Lukin1 and E. Demler1

1  Physics Department, Harvard University - Cambridge, MA - 02138, USA
2  QUANTOP, Danish National Research Foundation Centre of Quantum Optics, Niels Bohr Institute DK-2100 Copenhagen Ø, Denmark


received 20 September 2007; accepted in final form 2 November 2007; published January 2008
published online 27 November 2007

Abstract
We study Chern numbers to characterize the ground state of strongly interacting systems on a lattice. This method allows us to perform a numerical characterization of bosonic fractional quantum Hall (FQH) states on a lattice where the conventional overlap calculation with the known continuum case such as the Laughlin state, breaks down due to the lattice structure or dipole-dipole interaction. The non-vanishing Chern number indicates the existence of a topological order in the degenerate ground-state manifold.

PACS
03.75.Lm - Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations.
73.43.-f - Quantum Hall effects.

© EPLA 2008