One-dimensional optical lattices and impenetrable bosons

TL;DR

This paper investigates the behavior of strongly interacting bosons in one-dimensional optical lattices, deriving effective models, calculating energy corrections and correlations, and exploring phase transitions to novel quantum states.

Contribution

It introduces a continuum fermionic model from the Bose-Hubbard model at strong coupling and analyzes the resulting quantum phases and correlations.

Findings

Derived a continuum fermionic model from the lattice model.

Calculated energy corrections and pair correlations for the Tonks gas.

Discussed the potential realization of a Luttinger liquid with enhanced correlations.

Abstract

We study the limit of large onsite repulsion of the one-dimensional Bose-Hubbard model at low densities, and derive a strong-coupling effective Hamiltonian. By taking the lattice parameter to zero, the Hamiltonian becomes a continuum model of fermions with attractive interactions. The leading corrections to the internal energy of a hard-core-boson (Tonks) gas as well as the (finite temperature) pair correlations of a strongly interacting Bose gas are calculated. We explore the possibility of realizing, in an optical lattice, a Luttinger liquid with stronger density correlations than the Tonks gas. A quantum phase transition to a charge-density-wave Mott insulator is also discussed.