arXiv:1304.4258 · Physical Review B
Competing supersolids of Bose-Bose mixtures in a triangular lattice
Fabien Trousselet, Pamela Rueda‐Fonseca, Arnaud Ralko
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 tunneling and interactions. By combining three different methods, a self-consistent cluster mean-field, exact diagonalization, 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.