Prediction of quantum stripe ordering in optical lattices

TL;DR

This paper predicts a new quantum orbital stripe order in 2D optical lattices with cold bosons, breaking multiple symmetries and detectable via experimental signatures.

Contribution

It introduces a novel quantum orbital stripe order in the p-band Bose-Hubbard model, highlighting its symmetry-breaking and experimental detection methods.

Findings

Stripe order exists in superfluid and Mott phases

Order breaks time-reversal, translation, and rotation symmetries

Induces staggered plaquette bond currents

Abstract

We predict the robust existence of a novel quantum orbital stripe order in the $p$-band Bose-Hubbard model of two-dimensional triangular optical lattices with cold bosonic atoms. An orbital angular momentum moment is formed on each site exhibiting a stripe order both in the superfluid and Mott-insulating phases. The stripe order spontaneously breaks time-reversal, lattice translation and rotation symmetries. In addition, it induces staggered plaquette bond currents in the superfluid phase. Possible signatures of this stripe order in the time of flight experiment are discussed.