Local superconducting density of states of ErNi2B2C

TL;DR

This study uses tunnelling microscopy to investigate the local electronic states of ErNi2B2C, revealing deviations from conventional BCS superconductivity due to magnetic effects.

Contribution

It provides the first local density of states measurements of ErNi2B2C showing significant differences from standard s-wave BCS theory.

Findings

Finite density of states at the Fermi level in the superconducting state

Departure from conventional s-wave BCS behavior

Half of the normal state density of states observed

Abstract

We present local tunnelling microscopy and spectroscopy measurements at low temperatures in single crystalline samples of the magnetic superconductor ErNi2B2C. The electronic local density of states shows a striking departure from s-wave BCS theory with a finite value at the Fermi level, which amounts to half of the normal phase density of states.