Graphene spin capacitor for magnetic field sensing

TL;DR

This paper presents a novel graphene-based spin capacitor sensor capable of detecting very weak magnetic fields at room temperature by analyzing spin polarization dynamics.

Contribution

It introduces a new graphene spin capacitor design for magnetic sensing and analyzes its potential sensitivity and accuracy at room temperature.

Findings

Detects magnetic fields around 10 mOe at room temperature

Sensitivity depends on defect density and spin relaxation time

Proposes a feasible room-temperature magnetic field sensor

Abstract

An analysis of a novel magnetic field sensor based on a graphene spin capacitor is presented. The proposed device consists of graphene nanoribbons on top of an insulator material connected to a ferromagnetic source/drain. The time evolution of spin polarized electrons injected into the capacitor can be used for an accurate determination at room temperature of external magnetic fields. Assuming a spin relaxation time of 100 ns, magnetic fields on the order of $\sim 10$ mOe may be detected at room temperature. The observational accuracy of this device depends on the density of magnetic defects and spin relaxation time that can be achieved.