Estimation of the on-site Coulomb potential 1 and covalent state in La2CuO4 by muon spin rotation 2 and density functional theory calculations

TL;DR

This study combines muon spin rotation and density functional theory to accurately estimate the on-site Coulomb potential and covalent state in La2CuO4, shedding light on electronic interactions in high-Tc cuprates.

Contribution

It introduces a novel method integrating {bc}SR and DFT to determine Coulomb potential and covalent states in cuprates, providing detailed electronic structure insights.

Findings

Coulomb potential U estimated at 4.87 eV

Charge-transfer energy optimized at 1.24 eV

Local CuO6 deformations linked to muon injection

Abstract

The on-site Coulomb potential, U, and the covalent state of electronic orbitals play key roles for the Cooper pair symmetry and exotic electromagnetic properties of high-Tc superconducting cuprates. In this paper, we demonstrate a way to determine the value of U and present the whole picture of the covalent state of Cu spins in the mother system of the La-based high-Tc superconducting cuprate, La2CuO4, by combining the muon spin rotation ({\mu}SR) and the density functional theory (DFT) calculation. We reveal local deformations of the CuO6 octahedron followed by changes in Cu-spin distributions caused by the injected muon. Adjusting the DFT and muSR results, U and the minimum charge-transfer energy between the upper Hubbard band and the O 2p band were optimized to be 4.87(4) and 1.24(1) eV, respectively.