Colossal negative magnetoresistance in dilute fluorinated graphene

TL;DR

This paper reports the discovery of colossal negative magnetoresistance in dilute fluorinated graphene, showing significant resistance reduction under magnetic fields, with anisotropic behavior and potential quantum interference effects.

Contribution

It introduces a controlled, reversible method to create dilute fluorinated graphene and uncovers its unusual magnetoresistance properties at low carrier densities.

Findings

Zero-field resistance reduced by a factor of 40 at 9 T

Observation of staircase field dependence below 5 K

Magnetoresistance exhibits high anisotropy

Abstract

Adatoms offer an effective route to modify and engineer the properties of graphene. In this work, we create dilute fluorinated graphene using a clean, controlled and reversible approach. At low carrier densities, the system is strongly localized and exhibits an unexpected, colossal negative magnetoresistance. The zero-field resistance is reduced by a factor of 40 at the highest field of 9 T and shows no sign of saturation. Unusual "staircase" field dependence is observed below 5 K. The magnetoresistance is highly anisotropic. We discuss possible origins, considering quantum interference effects and adatom-induced magnetism in graphene.