Magnetic and Transport Properties of a Coupled Hubbard Bilayer with Electron and Hole Doping

TL;DR

This study investigates a bilayer Hubbard model with electron and hole doping, revealing potential d-wave pairing and magnetic properties, and compares findings to experimental cuprate materials.

Contribution

It demonstrates that a coupled bilayer Hubbard model with mixed doping can be studied at lower temperatures and shows signs of d-wave pairing, advancing understanding of high-temperature superconductivity.

Findings

Evidence of d-wave pairing in the bilayer model.

Magnetic properties similar to cuprate materials.

Phase diagram analysis of half-filled bilayer systems.

Abstract

The single band, two dimensional Hubbard Hamiltonian has been extensively studied as a model for high temperature superconductivity. While Quantum Monte Carlo simulations within the dynamic cluster approximation are now providing considerable evidence for a d-wave superconducting state at low temperature, such a transition remains well out of reach of finite lattice simulations because of the "sign problem". We show here that a bilayer Hubbard model, in which one layer is electron doped and one layer is hole doped, can be studied to lower temperatures and exhibits an interesting signal of d-wave pairing. The results of our simulations bear resemblance to a recent report on the magnetic and superconducting properties of Ba$_2$Ca$_3$Cu$_4$O$_8$F$_2$ which contains both electron and hole doped CuO$_2$ planes. We also explore the phase diagram of bilayer models in which each sheet is at half-filling.