Large magnetoresistance by Pauli blockade in hydrogenated graphene

Abstract

We report the observation of a giant positive magnetoresistance in millimetre scale hydrogenated graphene with magnetic field oriented in the plane of the graphene sheet. A positive magnetoresistance in excess of 200% at a temperature of 300 mK 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. Our work shows that spin polarization in concert with electron-electron interaction can play a dominant role in magnetotransport within an atomic monolayer.

Inducing a metal-insulator transition in disordered interacting Dirac fermion systems via an external magnetic field

“…These results also show that the magnetic field more strongly inhibits the metallic phase at lower temperatures, weaker interactions and weaker disorder. A similar phenomenon also occurs in a real material, hydrogenated graphene [48]. Lastly, we compile in Fig.…”

“…If now introducing a magnetic field, the increased spin polarization P favors localization in the system due to onset of Pauli blockade, which prevents the now more likely same-spin electrons to conduct. In this regime, the transport is more influenced on the maximum of n ↑ and n ↓ rather than on the total electron density n = n ↑ + n ↓ [48,50].…”