Transition between canted antiferromagnetic and spin-polarized ferromagnetic quantum Hall states in graphene on a ferrimagnetic insulator

TL;DR

This study demonstrates how magnetic proximity effects in graphene on a ferrimagnetic insulator enable tuning between antiferromagnetic and ferromagnetic quantum Hall states with relatively low magnetic fields, advancing control of 2D magnetic states.

Contribution

It reveals the influence of magnetic proximity coupling on the quantum Hall states in graphene, showing a tunable transition facilitated by an induced exchange field.

Findings

Induced magnetic exchange field in graphene lowers the transition field.

Transition between magnetic states can be controlled with magnetic fields > 6 T.

Proximity coupling enhances tunability of magnetic states in 2D materials.

Abstract

In the quantum Hall regime of graphene, antiferromagnetic and spin-polarized ferromagnetic states at the zeroth Landau level compete, leading to a canted antiferromagnetic state depending on the direction and magnitude of an applied magnetic field. Here, we investigate this transition at 2.7 K in graphene Hall bars that are proximity coupled to the ferrimagnetic insulator Y$_{3}$Fe$_{5}$O$_{12}$. From nonlocal transport measurements, we demonstrate an induced magnetic exchange field in graphene, which lowers the magnetic field required to modulate the magnetic state in graphene. These results show that a magnetic proximity effect in graphene is an important ingredient for the development of two-dimensional materials in which it is desirable for ordered states of matter to be tunable with relatively small applied magnetic fields (> 6 T).