Topological Flat Bands from Dipolar Spin Systems

TitleTopological Flat Bands from Dipolar Spin Systems
Publication TypeJournal Article
Year of Publication2012
AuthorsYao, NY, Laumann, CR, Gorshkov, AV, Bennett, SD, Demler, E, Zoller, P, Lukin, MD
JournalPhysical Review Letters
Date Published2012/12/26

We propose and analyze a physical system that naturally admits
two-dimensional topological nearly flat bands. Our approach utilizes an array
of three-level dipoles (effective S = 1 spins) driven by inhomogeneous
electromagnetic fields. The dipolar interactions produce arbitrary uniform
background gauge fields for an effective collection of conserved hardcore
bosons, namely, the dressed spin-flips. These gauge fields result in
topological band structures, whose bandgap can be larger than the corresponding
bandwidth. Exact diagonalization of the full interacting Hamiltonian at
half-filling reveals the existence of superfluid, crystalline, and supersolid
phases. An experimental realization using either ultra-cold polar molecules or
spins in the solid state is considered.

Short TitlePhys. Rev. Lett.