Ring Exchange and Phase Separation in the Two-dimensional Boson Hubbard model

Abstract

We present Quantum Monte Carlo simulations of the soft-core bosonic Hubbard model with a ring exchange term K. For values of K which exceed roughly half the on-site repulsion U, the density is a non-monotonic function of the chemical potential, indicating that the system has a tendency to phase separate. This behavior is confirmed by an examination of the density-density structure factor and real space images of the boson configurations. Adding a near-neighbor repulsion can compete with phase separation, but still does not give rise to a stable normal Bose liquid.

12 pages, 23 figures

References in corpus (15)

• Spin waves and electronic interactions in La2CuO4
• The one-dimensional Bose-Hubbard Model with nearest-neighbor interaction
• Strong-coupling expansions for the pure and disordered bose Hubbard model
• Phase separation in supersolids
• Ring exchange, the Bose metal, and bosonization in two dimensions
• Supersolids in the Bose-Hubbard Hamiltonian
• Striped phase in a quantum XY-model with ring exchange
• On the Coexistence of Diagonal and off-Diagonal Long-Range Order, a Monte Carlo Study
• Spin Excitations in La2CuO4: Consistent Description by Inclusion of Ring-Exchange
• Weak first-order superfluid--solid quantum phase transitions
• Derivation of effective spin models from a three band model for CuO_2-planes
• Two-Dimensional Quantum XY Model with Ring Exchange and External Field
• Mean Field Theory for Underdamped Josephson Junction Arrays with an Offset Voltage
• Bond and Neel order and fractionalization in ground states of easy-plane antiferromagnets in two dimensions
• Phase separation in the bosonic Hubbard model with ring exchange

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