Period 4 stripe in the extended two-dimensional Hubbard model

Stripe order in the underdoped region of the two-dimensional Hubbard model.

Competing inhomogeneous orders are a central feature of correlated electron materials, including the high-temperature superconductors. The two-dimensional Hubbard model serves as the canonical microscopic physical model for such systems. Multiple orders have been proposed in the underdoped part of the phase diagram, which corresponds to a regime of maximum numerical difficulty. By combining the...

Superconductivity in the two-dimensional Hubbard model.

A refined variational wave function for the two-dimensional repulsive Hubbard model is studied numerically , with the aim of approaching the difficult crossover regime of intermediate values of U. The issue of a superconducting ground state with d-wave symmetry is investigated for an average electron density n ≈ 0.8 and for U = 8t. Due to finite-size effects a clear-cut answer to this fundament...

Beyond extended dynamical mean-field theory: Dual boson approach to the two-dimensional extended Hubbard model

Broken Symmetries in the One-Dimensional Extended Hubbard Model

The past two decades have witnessed the discoveries of several new classes of novel electronic materials. Ranging from conducting polymers through charge transfer solids and inorganic chain compounds to organic and high temperature superconductors, these materials have in common two important, unusual properties. First, their electronic structures are strongly anisotropic, in some cases (e.g., ...

Enhanced Spin Susceptibility toward the Charge-Ordering Transition in a Two-Dimensional Extended Hubbard Model

Based on the non-skeleton diagrammatic expansion satisfying the compressibility and spinsusceptibility sum rules, we investigate static charge and spin responses in a two-dimensional extended Hubbard model with the nearest-neighbor Coulomb repulsion in the vicinity of its charge-ordering transition point. In this expansion, we can calculate approximate charge and spin response functions by syst...