Role of Inter-Electron Interaction in the Pseudo-Gap Opening in High T $_c$ Tunneling Experiments

TL;DR

This paper investigates how inter-electron interactions influence the pseudogap phenomenon in high-temperature superconductors, explaining tunneling experiment results through fluctuation theory and density of states renormalization.

Contribution

It introduces a fluctuation-based approach to interpret tunneling data, linking microscopic parameters to pseudogap features in high-Tc materials.

Findings

Explains the zero-bias conductance kink near Tc in YBaCuO/Pb junctions.

Qualitatively describes tunneling anomalies in G(V,T).

Accurately estimates pseudogap position and amplitude in BiSrCaCuO.

Abstract

The analysis of tunneling experiments showing the pseudogap type behavior is carried out based on the idea of the renormalization of density of states due to the inter-electron interaction in the Cooper channel (superconducting fluctuations contribution in tunneling current). It is demonstrated that the observed kink of the zero-bias conductance $G(0,T)$ of $YBaCuO/Pb$ junctions in the vicinity of $T_c$ can be explained in terms of fluctuation theory in a quite wide range of temperature above $T_c$, using the values of microscopic parameters of the $YBaCuO$ electron spectrum taken from independent experiments. The approach proposed also permits to explain qualitatively the shape of the tunneling anomalies in $G(V,T)$ and gives a correct estimate for the pseudogap position and amplitude observed in the experiments on $BiSrCaCuO$ junctions.