t-J model on the effective brick-wall lattice for the recently discovered high-temperature superconductor Ba$_2$CuO$_{3+δ}$

Zhan Wang; Sen Zhou; Wei-Qiang Chen; Fu-Chun Zhang

doi:10.1103/PhysRevB.101.180509

paper

t-J model on the effective brick-wall lattice for the recently discovered high-temperature superconductor Ba $_{2}$ CuO $_{3 + δ}$

arXiv:1912.12581 · doi:10.1103/PhysRevB.101.180509

Abstract

Layered copper oxides have highest superconducting transition temperatures at ambient pressure. Its mechanism remains a grand challenge in condensed matter physics. The essential physics lying in 2-dimensional copper-oxygen layers is well described by a single band Hubbard model or its strong coupling limit t-J model in 2-dimensional square lattice. Recently discovered high temperature superconductor Ba $_{2}$ CuO $_{3 + δ}$ with $δ \sim 0.2$ has different crystal structure with large portion of in-plane oxygen vacancies. We observe that an oxygen vacancy breaks the bond of its two neighboring copper atoms, and propose ordered vacancies in Ba $_{2}$ CuO $_{3 + δ}$ lead to extended t-J model on an effective brick-wall lattice. For the nearest neighbor hopping, the brick-wall model can be mapped onto t-J model on honeycomb lattice. Our theory explains the superconductivity of Ba $_{2}$ CuO $_{3 + δ}$ at high charge carrier density, and predict a time reversal symmetry broken pairing state.

to be published in PRB Rapid communications, 5 pages, 5 figures

t-J model on the effective brick-wall lattice for the recently discovered high-temperature superconductor Ba2​CuO3+δ​

Abstract

t-J model on the effective brick-wall lattice for the recently discovered high-temperature superconductor Ba $_{2}$ CuO $_{3 + δ}$