Quantum Anomalous Hall and Spin Hall Effects in Magnetic Graphene

Talieh S. Ghiasi, Davit Petrosyan, Josep Ingla-Aynés, Tristan Bras, Samuel Mañas-Valero, Kenji Watanabe, Takashi Taniguchi, Eugenio Coronado, Herre S. J. van der Zant

Published 2023-12-12Version 1

A promising approach to attain long-distance coherent spin propagation is accessing quantum Hall topological spin-polarized edge states in graphene. Achieving this without large external magnetic fields necessitates engineering graphene band structure, obtainable through proximity to 2D magnetic materials. In this work, we detect spin-polarized helical edge transport in graphene at zero external magnetic field, allowed by the out-of-plane magnetic proximity of CrPS$_4$ that spin-splits the zeroth Landau level. This zero-field detection of the quantum anomalous spin Hall state is enabled by large induced spin-orbit and exchange couplings in the graphene that also lead to the detection of an enhanced Berry curvature, shifting the Landau levels, and result in an unconventional sequence of quantum Hall plateaus. Remarkably, we observe that the quantum anomalous Hall transport in the magnetized graphene persists up to room temperature. The detection of spin-polarized helical edge states at zero magnetic field and the robustness of the quantum anomalous Hall transport up to room temperature open the route for practical applications of magnetic graphene in quantum information processing and spintronic circuitries.