Probing Spatial Correlations with Nanoscale Two-Contact Tunneling

TL;DR

This paper introduces a nanoscale two-contact tunneling method to investigate spatial correlations in superconductors, revealing how interference effects and gap anisotropy can probe the order parameter and intrinsic correlations.

Contribution

It presents a novel tunneling technique that relates differential conductance to spatial correlations, especially sensitive to gap anisotropy in high-temperature superconductors.

Findings

Interference effects reveal intrinsic spatial correlations.

Differential conductance relates to correlations in normal and superconducting samples.

Gap anisotropy significantly influences tunneling measurements.

Abstract

Interference effects on the transport through two localized tunnel junctions on the surface of a well-grounded sample reveal intrinsic spatial correlations characteristic of the uncoupled sample. Differential conductances of the two-junction probe are related to the spatial correlations of both normal and superconducting samples. For a superconducting sample the gap anisotropy strongly affects the results. This may serve as a sensitive probe of the order parameter in high-temperature superconductors.