Giant magnetoresistance by Pauli blockade in hydrogenated graphene

Giant magnetoresistance is a manifestation of spin dependent charge transport that encompasses a wide range of phenomena. The strength of the giant magnetoresistive effect has led to its application in the sensing of magnetic fields, most importantly in high density magnetic information storage. To date, in-plane magnetoresistive effects in atomically thin 2D electron systems have been found to be comparatively small [1].
We report the observation of a giant magnetoresistance in millimetre scale strongly insulating hydrogenated graphene with magnetic field oriented in the plane of the graphene sheet. A positive magnetoresistance in excess of 200% at a temperature of 300mK was observed in this configuration, reverting to negative magnetoresistance with the magnetic field oriented normal to the graphene plane.
We attribute the observed positive, in-plane, magnetoresistance to Pauli-blockade of hopping conduction induced by spin polarization [2]. Our work shows that spin polarization in concert with electron-electron interaction can play a dominant role in magnetotransport within an atomic monolayer.

[1] Chiappini, F., et al. Physical Review B 94.8 (2016): 085302.
[2] Matveev, K. A., et al. Physical Review B 52.7 (1995): 5289. Kamimura, H., et al. Physica B+ C 117 (1983): 652-654.