Inhomogeneity effects in oxygen doped HgBa$_2$CuO$_{4}$

TL;DR

This paper theoretically examines how inhomogeneities in oxygen-doped HgBa$_2$CuO$_{4}$ affect charge distribution, density of states, and superconductivity, revealing site-specific variations and their implications for experimental observations.

Contribution

It provides a detailed theoretical analysis of inhomogeneity effects on electronic properties in HgBa$_2$CuO$_{4+\delta}$, highlighting site-dependent doping effects and their influence on superconductivity.

Findings

Pronounced differences in hole concentration at different atomic sites.

Density of states near the Fermi level varies significantly with site and energy.

Inhomogeneities' impact on superconductivity depends on quasiparticle energy and nature.

Abstract

We theoretically investigate inhomogeneity effects on the charges, electric field gradients and site-projected densities of states in HgBa$_2$CuO$_{4+\delta}$. We find pronounced differences in the doping-induced number of holes at different atomic sites. The contributions of these sites to the density of states in the vicinity of the Fermi level are peaked at the same energy, but vary in magnitude by up to 70 percent and have different energy dependence. Due to this energy dependence the role of the intrinsic inhomogeneities for superconductivity strongly depends on the energy and character of the quasiparticle mediating the Cooper pairing. Our results can explain the origin of doping-induced effects observed either by local or macroscopic experimental probes.