Effects of extended correlated hopping in a bose-bose mixture

TL;DR

This paper investigates how extended correlated hopping influences phase behavior in a two-species Bose-Hubbard model, revealing novel phases like pair superfluidity and quantum droplets through combined theoretical methods.

Contribution

It introduces the effects of assisted tunneling in a bosonic system, expanding understanding of correlated hopping phenomena beyond fermionic models.

Findings

Identification of a pair superfluid phase due to interplay of hopping mechanisms

Discovery of a superfluid quantum droplet phase caused by large correlated hopping

Rich phase diagram including multiple novel quantum phases

Abstract

We study the effects of assisted tunneling or correlated hopping between next nearest neighbours in a two species Bose-Hubbard system. The system is the bosonic analong of the fermionic system studied in Phys. Rev. Lett. {\bf 116}, 225303 (2016). Using a combination of cluster mean field theory, exact diagonlization and analytical results, a rich phase diagram is determined including a pair superfluid phase as well as a superfluid quantum droplet phase. The former is the result of the interplay between single particle and correlated hopping, while the latter is the effect of large correlated hopping.