Bose-Hubbard model and superfluid staircases in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">He</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>4</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math></span> films

G. T. Zimanyi; P. A. Crowell; R. T. Scalettar; G. G. Batrouni

doi:10.1103/PhysRevB.50.6515

Rapid Communication

Bose-Hubbard model and superfluid staircases in ${}^{4}{He}$ films

G. T. Zimanyi, P. A. Crowell, R. T. Scalettar, and G. G. Batrouni

Phys. Rev. B 50, 6515(R) – Published 1 September 1994

Abstract

The recent experimental observation of steplike structure in the superfluid density of ${}^{4}{He}$ films on graphite is interpreted in terms of passage close to Mott insulating lobes in the Bose-Hubbard model. Plateaus develop in the superfluid density near the completion of each layer because of the He-He repulsion. We modify the Bose-Hubbard Hamiltonian, using a density-dependent He-He interaction term to model the He-substrate potential. Quantum Monte Carlo simulations yield results that agree well with the experimental data.

DOI:https://doi.org/10.1103/PhysRevB.50.6515