Spin-filtering in superconducting junction with the manganite interlayer

TL;DR

This paper investigates how spin-filtering affects electronic transport in superconducting junctions with a manganite interlayer, revealing temperature-dependent behavior and magnetic field sensitivity.

Contribution

It demonstrates the impact of manganite interlayer thickness on tunneling barrier height and confirms spin filtering through magneto-resistance measurements.

Findings

Barrier height decreases exponentially with interlayer thickness.

Conductivity temperature dependence aligns with d-wave superconductivity and spin filtering.

Mesa-structure conductivity is highly sensitive to weak magnetic fields.

Abstract

We report on the electronic transport and the impact of spin-filtering in mesa-structures made of epitaxial thin films of cuprate superconductor YBa2Cu3Ox(YBCO) and the manganite LaMnO3 (LMO) interlayer with the Au/Nb counterelectrode. Ferromagnetic resonance measurements of heterostructure Au/LMO/YBCO shows ferromagnetic state at temperatures below 150 K as in the case of reference LMO film grown on the neodymium gallate substrate. The heights of the tunneling barrier evaluated from resistive characteristics of mesa-structures at different thickness of interlayer showed an exponential decrease from 30 mV down to 5 mV with the increase of manganite interlayer thickness. Temperature dependence of the conductivity of mesa-structures could be described taking into account the d-wave superconductivity in YBCO and a spin filtering of the electron transport. Spin filtering is supported also by measurements of magneto-resistance and the high sensitivity of mesa-structure conductivity to weak magnetic fields.