Tunneling conductance and local density of states in tight-binding junctions

TL;DR

This paper investigates how tunneling conductance relates to local density of states in tight-binding junctions, highlighting the impact of junction geometry and matrix elements, with implications for STM data interpretation.

Contribution

It provides a detailed analysis of conductance and local density of states in various junction geometries using the real-space Keldysh formalism, addressing STM spectroscopic interpretation.

Findings

Conductance varies significantly between point-contact and planar-contact limits.

Matrix elements influence tunneling characteristics and contrast.

Implications for interpreting STM data in cuprates.

Abstract

We study the relationship between the differential conductance and the local density of states in tight-binding tunnel junctions where the junction' geometry can be varied between the point-contact and the planar-contact limits. The conductances are found to differ significantly in these two limiting cases. We also examine how the matrix element influences the tunneling characteristics and produces contrast in a simple model of scanning tunneling microscope (STM). Some implications regarding the interpretation of STM spectroscopic data in the cuprates are discussed. The calculations are carried out within the real-space Keldysh formalism.