A stable Algebraic Spin Liquid in a Hubbard model

TL;DR

This paper demonstrates a stable Algebraic Spin Liquid phase in a honeycomb lattice Hubbard model with spin-dependent hopping, protected by time-reversal symmetry, and discusses its realization in cold atom systems.

Contribution

It establishes the stability of an Algebraic Spin Liquid in a Hubbard model with spin-dependent hopping, linking it to the Kitaev model and providing experimental proposals.

Findings

Existence of a stable ASL phase in the model

Protection of Majorana fermions by TR symmetry

Potential realization in cold atom experiments

Abstract

We show the existence of a stable Algebraic Spin Liquid (ASL) phase in a Hubbard model defined on a honeycomb lattice with spin-dependent hopping that breaks time-reversal symmetry. The effective spin model is the Kitaev model for large on-site repulsion. The gaplessness of the emergent Majorana fermions is protected by the time reversal (TR) invariance of this model. We prove that the effective spin model is TR invariant in the entire Mott phase thus ensuring the stability of the ASL. The model can be physically realized in cold atom systems and we propose experimental signals of the ASL.