  We report an experimental study of electron transport properties of
MnSe/(Bi,Sb)2Te3 heterostructures, in which MnSe is an antiferromagnetic
insulator, and (Bi,Sb)2Te3 is a three-dimensional topological insulator (TI).
Strong magnetic proximity effect is manifested in the measurements of the Hall
effect and longitudinal resistances. Our analysis shows that the gate voltage
can substantially modify the anomalous Hall conductance, which exceeds 0.1 e2/h
at temperature of 1.6 K and magnetic field of 5 T, even though only the top TI
surface is in proximity to MnSe. This work suggests that heterostructures based
on antiferromagnetic insulators provide a promising platform for investigating
a wide range of topological spintronic phenomena.
