Matter waves in atomic artificial graphene

¹ Université Montpellier 2, Laboratoire Charles Coulomb UMR 5221 - F-34095 Montpellier, France
² CNRS, Laboratoire Charles Coulomb UMR 5221 - F-34095 Montpellier, France
³ INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento - I-38123 Povo, Italy
⁴ Institut Universitaire de France - 103, bd Saint- Michel, F-75005 Paris, France

^(a) nicola.bartolo@univ-montp2.fr
^(b) mauro.antezza@univ-montp2.fr

Received: 28 May 2014
Accepted: 17 July 2014

Abstract

We present a new model to realize artificial 2D lattices with cold atoms investigating the atomic artificial graphene: a 2D confined matter wave is scattered by atoms of a second species trapped around the nodes of a honeycomb optical lattice. The system allows an exact determination of the Green function, hence of the transport properties. The inter-species interaction can be tuned via the interplay between scattering length and confinements. Band structure and density of states of a periodic lattice are derived for different values of the interaction strength. Emergence and features of Dirac cones are pointed out, together with the appearance of multiple gaps and a non-dispersive and isolated flat band. Robustness against finite-size and vacancies effects is numerically investigated.