Circuit model for spin-bottleneck resistance in magnetic-tunnel-junction devices

TL;DR

This paper introduces a simple electrical circuit model that captures spin-bottleneck effects in magnetic-tunnel-junction devices, enabling analysis of resistance and magnetoresistance based on spin-dependent properties.

Contribution

A novel circuit model for magnetic-tunnel-junction devices that incorporates spin-bottleneck effects and aligns well with detailed transport calculations.

Findings

Model accurately predicts device resistance and magnetoresistance.

Dependence on spin diffusion lengths and spin resistivities is clearly demonstrated.

Quantitative agreement with detailed transport calculations is achieved.

Abstract

Spin-bottlenecks are created in magnetic-tunnel-junction devices by spatial inhomogeneity in the relative resistances for up and down spins. We propose a simple electrical circuit model for these devices which incorporates spin-bottleneck effects and can be used to calculate their overall resistance and magnetoresistance. The model permits a simple understanding of the dependence of device magnetoresistance on spin diffusion lengths, tunneling magnetoresistance, and majority and minority spin resistivities in the ferromagnetic electrodes. The circuit model is in a good quantitative agreement with detailed transport calculations.