Quantum phases of Bose-Bose mixtures on a triangular lattice

TL;DR

This paper explores the diverse quantum phases of a Bose-Bose mixture on a triangular lattice at zero temperature, revealing complex magnetic, superfluid, and supersolid states influenced by geometric frustration.

Contribution

It provides the first detailed phase diagram of Bose-Bose mixtures on a triangular lattice considering asymmetric hopping and geometric frustration effects.

Findings

Identification of xy-ferromagnetic, spin-density wave, superfluid, and supersolid phases.

Discovery of a stripe spin-density wave phase under high asymmetry.

Observation of weak charge density wave order on top of spin-density wave.

Abstract

We investigate the zero temperature quantum phases of a Bose-Bose mixture on a triangular lattice using Bosonic Dynamical Mean Field Theory (BDMFT). We consider the case of total filling one where geometric frustration arises for asymmetric hopping. We map out a rich ground state phase diagram including xy-ferromagnetic, spin-density wave, superfluid, and supersolid phases. In particular, we identify a stripe spin-density wave phase for highly asymmetric hopping. On top of the spin-density wave, we find that the system generically shows weak charge (particle) density wave order.