Bose-Hubbard model and superfluid staircases in 4He films
Abstract
The recent experimental observation of steplike structure in the superfluid density of 4He 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.
- Publication:
-
Physical Review B
- Pub Date:
- September 1994
- DOI:
- 10.1103/PhysRevB.50.6515
- arXiv:
- arXiv:cond-mat/9310058
- Bibcode:
- 1994PhRvB..50.6515Z
- Keywords:
-
- 67.70.+n;
- 05.30.Jp;
- 67.40.Rp;
- Films;
- Boson systems;
- Films and weak link transport;
- Condensed Matter
- E-Print:
- 11 pages+3 figures upon request, Revtex 3.0, UCD 93-112