Parity‐Anomaly Quantum Anomalous Hall State in Mechanically Assembled Topological Insulator/Magnet Heterostructures

The family of quantized anomalous Hall effects provides remarkable electronic properties—for example, current flow perpendicular to the voltage and, in some cases, dissipationless edge states even with zero applied magnetic field, B —but their development is limited by their realization only at very low temperatures. The state of the art in magnetically‐doped topological insulators (TIs) currently allows quantized Hall conductivities to persist up to temperatures of several Kelvin. An alternative approach, proximity‐coupled TI/magnet heterostructures made using a chemically separate magnet, has up until now been more limited, with Hall quantization either completely absent or present only below 100 mK at B = 0. Here, we demonstrate one in the family of quantized anomalous Hall effects, the parity anomaly state (with Hall conductivity e 2 /2h) at temperatures up to 10 K in TI/magnet bilayers made by mechanical assembly of van der Waals layers. This represents an enhancement by a factor of 100 compared to previous proximity‐coupled heterostructures grown by deposition.