Zero-bias conductance peak splitting due to multiband effect in tunneling spectroscopy

TL;DR

This paper investigates how multiband effects influence zero-bias conductance peaks in tunneling spectroscopy, proposing that peak splitting can serve as a probe for pairing symmetry in organic superconductors.

Contribution

It demonstrates that Fermi surface multiplicity can cause ZBCP splitting and suggests using this as a diagnostic tool for pairing symmetry in specific organic superconductors.

Findings

Fermi surface multiplicity can cause ZBCP splitting.

ZBCP splitting can distinguish pairing symmetries.

Proposed tunneling spectroscopy as a probe for pairing symmetry.

Abstract

We study how the multiplicity of the Fermi surface affects the zero-bias peak in conductance spectra of tunneling spectroscopy. As case studies, we consider models for organic superconductors $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ and (TMTSF)$_2$ClO$_4$. We find that multiplicity of the Fermi surfaces can lead to a splitting of the zero-bias conductance peak (ZBCP). We propose that the presence/absence of the ZBCP splitting is used as a probe to distinguish the pairing symmetry in $\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$.