The Enormous Anomalous Hall Effect in (Bi,Sb)2Te3/ Europium Iron Garnet Heterostructures

To realize the quantum anomalous Hall effect (QAHE) at elevated temperatures, we adopted the approach of magnetic proximity effect (MPE) to break time-reversal symmetry in the topological insulator (Bi,Sb)2Te3 (BST) based heterostructure with a ferromagnetic insulator like europium iron garnet (EuIG) of perpendicular magnetic anisotropy. Here we demonstrated phenomenally large anomalous Hall resistance (RAHE) as high as 8 Ω at 300 K, and sustained to 400 K in 35 BST/EuIG samples, surpassing the past record (0.28 Ω) by nearly thirty times. These striking results are attributed