  Spin-based electronics in topological insulators (TIs) is favored by the long
spin coherence1,2 and consequently fault-tolerant information storage.
Magnetically doped TIs are ferromagnetic up to 13 K,3 well below any practical
operating condition. Here we demonstrate that the long range ferromagnetism at
ambient temperature can be induced in Bi2-xMnxTe3 by the magnetic proximity
effect through deposited Fe overlayer. This result opens a new path to
interface-controlled ferromagnetism in TI-based spintronic devices.
