Effect of superlattice modulation of electronic parameters on superconducting density of states in cuprate superconductors

TL;DR

This paper investigates how superlattice modulations in cuprate superconductors influence the local superconducting gap, using a theoretical model that aligns well with experimental observations from scanning tunneling microscopy.

Contribution

It introduces a microscopic model linking atomic superlattice modulations to superconducting gap variations in cuprates, validated by theoretical calculations matching experimental data.

Findings

Superlattice modulations cause significant spatial variations in the superconducting gap.

Theoretical estimates align well with STM experimental results.

Superlattice effects are crucial for understanding inhomogeneities in cuprate superconductors.

Abstract

Recent scanning tunneling microscopy on BSCCO 2212 has revealed a substantial spatial supermodulation of the energy gap in the superconducting state. We propose that this gap modulation is due to the superlattice modulations of the atoms in the structure, and hence the parameters in a microscopic model of the CuO2 plane. The gap modulation is estimated using renormalized mean field theory for a t-t'-J model on a superlattice. The results compare well with experiment.