Order parameter oscillations in Fe/Ag/Bi2Sr2CaCu2O{8+delta} tunnel junctions

TL;DR

This study investigates the temperature-dependent tunneling conductance in Fe/Ag/Bi2Sr2CaCu2O8 junctions, revealing oscillatory behavior consistent with theoretical models of d-wave superconductors coupled with ferromagnets, and detecting signatures of broken time-reversal symmetry.

Contribution

It provides experimental evidence of order parameter oscillations and broken time-reversal symmetry in Fe/Ag/Bi2Sr2CaCu2O8 junctions, advancing understanding of superconductor-ferromagnet interactions.

Findings

Conductance spectra show coherent oscillations with energy-dependent magnitude and sign.

Oscillations decay with distance from the junction barrier.

Spectral features indicate broken time-reversal pairing symmetry.

Abstract

We have performed temperature dependent tunneling conductance spectroscopy on Fe/Ag/Bi2Sr2CaCu2O8 (BSCCO) planar junctions. The multilayered Fe counterelectrode was designed to probe the proximity region of the ab-plane of BSCCO. The spectra manifested a coherent oscillatory behavior with magnitude and sign dependent on the energy, decaying with increasing distance from the junction barrier, in conjunction with the theoretical predictions involving d-wave superconductors coupled with ferromagnets. The conductance oscillates in antiphase at E = 0 and E = +/-Delta. Spectral features characteristic to a broken time-reversal pairing symmetry are detected and they do not depend on the geometrical characteristics of the ferromagnetic film.