AIP conference proceedings
Phase Diagram of the S = 1 Bilinear Biquadratic Model
Kenji Harada, Naoki Kawashima, Matthias Troyer
Abstract
The S = 1 bilinear biquadratic model is an effective spin model for 23Na atoms in an optical lattice. We study the ground state in one and two dimensions through quantum Monte Carlo simulations using a non‐binary loop algorithm which was recently proposed. In one dimension, the critical quadrupolar phase argued by Läuchli is not confirmed in quantum Monte Carlo simulations. In two dimensions, simulation results show a direct phase transition between dimer and quadrupolar phases where the coupling constant between chains becomes large.