# Spin transport parameters of NbN thin films characterised by spin pumping experiments

## TL;DR

This study measures spin transport parameters in NbN thin films using spin pumping and inverse spin-Hall effect experiments, providing key data for superconducting spintronics development.

## Contribution

It introduces a method to quantify spin diffusion length, spin Hall angle, and interface conductance in NbN thin films through experimental and theoretical analysis.

## Key findings

- Spin diffusion length in NbN is 14 nm.
- Spin Hall angle in NbN is -1.1×10^-2.
- Spin-mixing conductance at NbN/YIG interface is 10 nm^-2.

## Abstract

We present measurements of ferromagnetic-resonance - driven spin pumping and inverse spin-Hall effect in NbN/Y3Fe5O12 (YIG) bilayers. A clear enhancement of the (effective) Gilbert damping constant of the thin-film YIG was observed due to the presence of the NbN spin sink. By varying the NbN thickness and employing spin-diffusion theory, we have estimated the room temperature values of the spin diffusion length and the spin Hall angle in NbN to be 14 nm and -1.1 10-2, respectively. Furthermore, we have determined the spin-mixing conductance of the NbN/YIG interface to be 10 nm-2. The experimental quantification of these spin transport parameters is an important step towards the development of superconducting spintronic devices involving NbN thin films.

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Source: https://tomesphere.com/paper/1901.05753