Competing supersolids of Bose-Bose mixtures in a triangular lattice

TL;DR

This paper explores the complex phase diagram of a frustrated two-species hard-core boson mixture on a triangular lattice, revealing three novel supersolid phases influenced by tunable interactions and quantum fluctuations.

Contribution

It introduces three original mixture supersolids and demonstrates their stabilization mechanisms using combined theoretical methods.

Findings

Identification of three novel supersolid phases.

Demonstration of phase stabilization via quantum fluctuations.

Rich and complex phase diagram of Bose-Bose mixtures on a triangular lattice.

Abstract

We study the ground state properties of a frustrated two-species mixture of hard-core bosons on a triangular lattice, as a function of tunable amplitudes for tunnelling and interactions. By combining three different methods, a self-consistent cluster mean-field, exact diagonalizations and effective theories, we unravel a very rich and complex phase diagram. More specifically, we discuss the existence of three original mixture supersolids: (i) a commensurate with frozen densities and supersolidity in spin degrees of freedom, in a regime of strong interspecies interactions; and (ii) when this interaction is weaker, two mutually competing incommensurate supersolids. Finally, we show how these phases can be stabilized by a quantum fluctuation enhancement of peculiar insulating parent states.