Quantum Phases of Ultracold Bosonic Atoms in a One Dimensional Optical Superlattice

TL;DR

This paper investigates the quantum phases of ultracold bosonic atoms in a one-dimensional optical superlattice using the DMRG method within the Bose-Hubbard model, revealing various insulating and superfluid states.

Contribution

It provides a detailed analysis of quantum phase behavior in a superlattice, including the effects of superlattice potential and density variations, using advanced numerical techniques.

Findings

Identification of Mott insulator and superfluid phases at commensurate fillings.

Discovery of superlattice-induced Mott insulators.

Observation of superfluid phase with density oscillations at incommensurate densities.

Abstract

We analyze various quantum phases of ultracold bosonic atoms in a periodic one dimensional optical superlattice. Our studies have been performed using the finite size density matrix renormalization group (FS-DMRG) method in the framework of the Bose-Hubbard model. Calculations have been carried out for a wide range of densities and the energy shifts due to the superlattice potential. At commensurate fillings, we find the Mott insulator and the superfluid phases as well as Mott insulators induced by the superlattice. At a particular incommensurate density, the system is found to be in the superfluid phase coexisting with density oscillations for a certain range of parameters of the system.