Frustrated extended Bose-Hubbard model and deconfined quantum critical points with optical lattices at the anti-magic wavelength

TL;DR

This paper proposes a scheme using ultracold bosons in optical lattices to realize a frustrated Bose-Hubbard model, revealing novel quantum phases and a deconfined quantum critical point in one dimension.

Contribution

It introduces a tunable frustrated Bose-Hubbard model with optical lattices, identifying new quantum phases and demonstrating a continuous phase transition as a deconfined quantum critical point.

Findings

Discovery of bond-order-wave insulator and chiral superfluid phases

Identification of a density-wave insulator with broken translational symmetry

Observation of a continuous phase transition as a deconfined quantum critical point

Abstract

The study of geometrically frustrated many-body quantum systems is of central importance to uncover novel quantum mechanical effects. We design a scheme where ultracold bosons trapped in a one-dimensional state-dependent optical lattice are modeled by a frustrated Bose-Hubbard Hamiltonian. A derivation of the Hamiltonian parameters based on Cesium atoms, further show large tunability of contact and nearest-neighbour interactions. For pure contact repulsion, we discover the presence of two phases peculiar to frustrated quantum magnets: the bond-order-wave insulator with broken inversion symmetry and a chiral superfluid. When the nearest-neighbour repulsion becomes sizeable, a further density-wave insulator with broken translational symmetry can appear. We show that the phase transition between the two spontaneously-symmetry-broken phases is continuous, thus representing a one-dimensional deconfined quantum critical point not captured by the Landau-Ginzburg-Wilson symmetry-breaking paradigm. Our results provide a solid ground to unveil the novel quantum physics induced by the interplay of non-local interactions, geometrical frustration, and quantum fluctuations.