Magnetic Ordering in Blocking Layer and Highly Anisotropic Electronic Structure of High-Tc Iron-based Superconductor Sr2VFeAsO3: LDA+U Studies

TL;DR

This study uses LDA+U calculations to show that magnetic ordering in the blocking layers of Sr2VFeAsO3 makes them insulating, leading to high anisotropy and potential new Josephson effects in this high-Tc superconductor.

Contribution

It demonstrates that including strong correlation effects transforms the blocking layers into insulators, aligning the Fermi surface with other iron-based superconductors and predicting novel transport phenomena.

Findings

Blocking layers become insulating with LDA+U

Fermi surface resembles other iron-based superconductors

High anisotropy and intrinsic Josephson effects predicted

Abstract

We calculate electronic structures of a high-Tc iron-based superconductor Sr2VFeAsO3 by LDA+U method. We assume a checker-board antiferromagnetic order on blocking layers including vanadium and strong correlation in d-orbits of vanadium through the Hubbard U. While the standard LDA brings about metallic blocking layers and complicated Fermi surface as in the previous literatures, our calculation changes the blocking layer into insulating one and the Fermi surface becomes quite similar to those of other iron-based superconductors. Moreover, the appearance of the insulating blocking layers predicts high anisotropy on quasi-particle transports and new types of intrinsic Josephson effects.