Hanle lineshapes and spin-rotation signatures from in-plane anisotropic spin relaxation in heterogeneous spin devices

TL;DR

This paper develops a theoretical framework using the Bloch diffusion equation to analyze spin precession signals in heterogeneous spintronic devices, especially focusing on in-plane anisotropic spin relaxation in graphene-based systems.

Contribution

It introduces a model for interpreting spin transport measurements in lateral graphene spin devices with anisotropic spin relaxation regions, accounting for device geometry and material heterogeneity.

Findings

Spin precession lineshapes are affected by in-plane anisotropic relaxation.

The model matches experimental data in proximitized graphene devices.

Insights into the role of device geometry on spin signals.

Abstract

Spin precession experiments in lateral spin devices are a powerful tool for probing the spin transport properties of materials. These experiments can be quantitatively described using the Bloch diffusion equation, which offers a practical framework for modeling spin-related phenomena. In this work, we present calculations of the spin density across heterogeneous, diffusive spintronic devices. The modeled devices feature spin transport channels that include both isotropic and in-plane anisotropic spin relaxation regions. We analyze how different geometric configurations and spin transport parameters influence the lineshape of spin precession signals under magnetic fields applied in different orientations and compare with experimental observations. Our results introduce a theoretical framework for interpreting spin transport measurements in lateral graphene spin devices. The framework is especially relevant when the graphene is partially proximitized by other two-dimensional materials, where proximity-induced spin-orbit coupling leads to anisotropic spin relaxation.