Spin wave theory for interacting hardcore bosons on cubic lattices: a comparative study
arXiv:1212.5191
Abstract
Motivated by excellent comparisons of spin wave theory (SWT) with Quantum Monte Carlo (QMC) calculations of non-interacting hardore bosons (Bernardet et al.) and superlattices (Hen et al.), we develop an SWT for interacting hardcore bosons on a d-dimensional cubic lattice at zero temperature and compare thermodynamical properties with results of Stochastic Series Expansions (SSE): there is good comparison between SWT and SSE results for the simple cubic lattice at small repulsive strengths but differences arise between the results of the two approaches for the square lattice at strong repulsions. The boundaries of the three phases - Mott insulating (MI), superfluid (SF) and Néel solid (NS) - can be readily estimated from calculations of particle density, signalling either a first order (SF <--> NS) or second order transition (MI <--> SF). Comparison is made with results of the Bethe ansatz in one dimension and QMC in two dimensions.
arXiv comment5 pages, 4 figures, 2 column format
References in corpus (4)
- Simultaneous Diagonal and Off Diagonal Order in the Bose--Hubbard Hamiltonian
- Analytical and numerical study of hardcore bosons in two dimensions
- Superfluid to Mott-insulator transition of hardcore bosons in a superlattice
- Phase diagrams, critical and multicritical behavior of hard-core Bose-Hubbard models