Hard-core bosons on the kagome lattice: valence-bond solids and their quantum melting.
Using large scale quantum Monte Carlo simulations and dual vortex theory, we analyze the ground state phase diagram of hard-core bosons on the kagome lattice with nearest-neighbor repulsion. In contrast with the case of a triangular lattice, no supersolid emerges for strong interactions. While a uniform superfluid prevails at half filling, two novel solid phases emerge at densities rho=1/3 and rho=2/3. These solids exhibit an only partial ordering of the bosonic density, allowing for local resonances on a subset of hexagons of the kagome lattice. We provide evidence for a weakly first-order phase transition at the quantum melting point between these solid phases and the superfluid.
Isakov
S V
SV
Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada.
Wessel
S
S
Melko
R G
RG
Sengupta
K
K
Kim
Yong Baek
YB