Giant Gate-Controlled Odd-Parity Magnetoresistance in Magnetized Bilayer Graphene at Room Temperature.

Abstract

In this Letter, we report the discovery of giant room-temperature odd-parity magnetoresistance (OMR) in a bilayer graphene heterostructure interfaced with Cr_{2}Ge_{2}Te_{6} (CGT). We show that the OMR is electrostatic gate-voltage tunable, exhibiting maximum value near the graphene band edges and diminishing rapidly with increasing charge carrier density. Our theoretical analysis reveals that the OMR originates from the coupling of out-of-plane components of Berry curvature and orbital magnetic moment with the applied magnetic field, signaling intrinsic time-reversal symmetry breaking in the system. This time-reversal symmetry breaking persists at room temperature within the CGT and bilayer graphene heterostructure despite the bulk CGT exhibiting ferromagnetic transition at 65 K. Our Letter opens new avenues for probing band geometric phenomena through magnetotransport measurements, especially in quantum materials where the anomalous Hall effects are immeasurably small due to the extrinsic scattering-dependent contributions canceling Berry curvature contributions.