Phase diagram of the square lattice bilayer Hubbard model: a variational Monte Carlo study

Abstract

We investigate the phase diagram of the square lattice bilayer Hubbard model at half filling with the variational Monte Carlo method for both the magnetic and the paramagnetic case as a function of interlayer hopping t_perp and on-site Coulomb repulsion U. With this study we resolve some discrepancies in previous calculations based on the dynamical mean field theory, and we are able to determine the nature of the phase transitions between metal, Mott insulator and band insulator. In the magnetic case we find only two phases: An antiferromagnetic Mott insulator at small t_perp for any value of U and a band insulator at large t_perp. At large U values we approach the Heisenberg limit. The paramagnetic phase diagram shows at small t_perp a metal to Mott insulator transition at moderate U values and a Mott to band insulator transition at larger U values. We also observe a reentrant Mott insulator to metal transition and metal to band insulator transition for increasing t_perp in the range of 5.5t < U < 7.5t. Finally, we discuss the obtained phase diagrams in relation to previous studies based on different many-body approaches.

18 pages, 10 figures

References in corpus (7)

• Phase diagram of the one-dimensional half-filled extended Hubbard model
• Role of backflow correlations for the non-magnetic phase of the t-t' Hubbard model
• Band insulator to Mott insulator transition in a bilayer Hubbard model
• Metallic phase in the two-dimensional ionic Hubbard model
• Magnetic and Transport Properties of a Coupled Hubbard Bilayer with Electron and Hole Doping
• Correlations in a band insulator
• Magnetic transition in a correlated band insulator

Cited by in corpus (17)

• Competing magnetic orders in a bilayer Hubbard model with ultracold atoms
• Effect of interlayer processes on the superconducting state within t-J-U model: Full Gutzwiller wave-function solution and relation to experiment
• Metal-insulator transitions, superconductivity, and magnetism in the two-band Hubbard model
• Nonlocal density interactions in auxiliary-field quantum Monte Carlo simulations: application to the square lattice bilayer and honeycomb lattice
• Numerical stabilization of entanglement computation in auxiliary field quantum Monte Carlo simulations of interacting many-fermion systems
• Ground state phase diagram of the half-filled bilayer Hubbard model
• Superfluidity and Density Order in a Bilayer Extended Hubbard Model
• Bilayer Hubbard model: Analysis based on the fermionic sign problem
• Entanglement properties of the antiferromagnetic-singlet transition in the Hubbard model on bilayer square lattices
• Assessing the orbital selective Mott transition with variational wave functions
• Gutzwiller variational wave function for multi-orbital Hubbard models in finite dimensions
• Continuous Mott Transition in a Two-Dimensional Hubbard Model
• Electrically driven insulator-to-metal transition in a correlated insulator: Electronic mechanism and thermal description
• Site-selective insulating phase in twisted bilayer Hubbard model
• Interlayer Hopping between Surface Mott Insulator and Bulk Band Insulator in layered 1T-TaS_{2}
• Interplay of disorder and interactions in the bilayer band-insulator : A determinant quantum Monte Carlo study
• Quantum Phase transition in the two dimensional ionic-Hubbard model