Nonlinear interaction of spin and charge currents in graphene

TL;DR

This paper explores a nonlinear interaction between charge and spin currents in graphene, enabling nonmagnetic control and measurement of spin signals, with potential amplification of spin accumulation in p-n junctions.

Contribution

It introduces a novel nonlinear interaction mechanism in graphene that links charge and spin currents, expanding the methods for spin signal manipulation.

Findings

Nonmagnetic contacts can measure and control spin signals.

Amplification of spin accumulation is demonstrated in p-n junctions.

Predicted effects are significant in nonlocal spin valve devices.

Abstract

We describe a nonlinear interaction between charge currents and spin currents which arises from the energy dependence of the conductivity. This allows nonmagnetic contacts to be used for measuring and controlling spin signals. We choose graphene as a model system to study these effects and predict its magnitudes in nonlocal spin valve devices. The ambipolar behavior of graphene is used to demonstrate amplification of spin accumulation in p-n junctions by applying a charge current through nonmagnetic contacts.