Controlling two-species Mott-insulator phses in an optical lattice to form an array of dipolar molecules

TL;DR

This paper explores how to control two-species Mott-insulator phases in optical lattices to create arrays of dipolar molecules, which are promising for quantum computing and condensate formation.

Contribution

It demonstrates how varying lattice parameters can enable the formation of mixed Mott-insulator phases suitable for dipolar molecule creation.

Findings

Optimal lattice frequency regimes identified for dipolar molecule formation.

Large inter-species scattering length challenges the realization of mixed phases.

Parameter tuning can facilitate the creation of dipolar molecular arrays.

Abstract

We consider the transfer of a two-species Bose-Einstein condensate into an optical lattice with a density such that that a Mott-insulator state with one atom per species per lattice site is obtained in the deep lattice regime. Depending on collision parameters the result could be either a `mixed' or a `separated' Mott-insulator phase. Such a `mixed' two-species insulator could then be photo-associated into an array of dipolar molecules suitable for quantum computation or the formation of a dipolar molecular condensate. For the case of a $^{87}$Rb-$^{41}$K two-species BEC, however, the large inter-species scattering length makes obtaining the desired `mixed' Mott insulator phase difficult. To overcome this difficulty we investigate the effect of varying the lattice frequency on the mean-field interaction and find a favorable parameter regime under which a lattice of dipolar molecules could be generated.