Imaging the Spatial Form of a Superconducting Order Parameter via Josephson Scanning Tunneling Spectroscopy

TL;DR

This paper demonstrates how Josephson scanning tunneling spectroscopy can spatially image the superconducting order parameter's form and defect-induced phase transitions in an s-wave superconductor, offering new insights into superconductivity.

Contribution

It introduces a method to visualize the spatial oscillations of the order parameter caused by defects using local Josephson current measurements.

Findings

Spatial oscillations in the order parameter can be imaged.

Josephson current reflects defect characteristics.

Probing defect-induced phase transitions.

Abstract

Motivated by recent experiments, we investigate Josephson scanning tunneling spectroscopy in an s-wave superconductor. We demonstrate that the spatial oscillations in the superconducting order parameter induced by defects can be spatially imaged through local measurements of the critical Josephson current, providing unprecedented insight into the nature of superconductivity. The spatial form of the Josephson current reflects the nature of the defects, and can be used to probe defect-induced phase transitions from an $S=0$ to an $S=1/2$ ground state.