Ferromagnetic phase transition in topological crystalline insulator thin films: Interplay of anomalous Hall angle and magnetic anisotropy

摘要

In magnetic topological phases of matter, the quantum anomalous Hall (QAH) effect is an emergent phenomenon driven by ferromagnetic doping, magnetic proximity effects, and strain engineering. The realization of QAH states with multiple dissipationless edge and surface conduction channels defined by a Chern number C = 1 was foreseen for the ferromagnetically ordered SnTe class of topological crystalline insulators (TCIs). From magnetotransport measurements on Sn1-xMnxTe (0.00 = x = 0.08) (111) epitaxial thin films grown by molecular beam epitaxy on BaF2 substrates, hole-mediated ferromagnetism is observed in samples with x = 0.06 and the highest T-c similar to 7.5 K is inferred from an anomalous Hall behavior in Sn0.92Mn0.08Te. The sizable anomalous Hall angle similar to 0.3 obtained for Sn0.92Mn0.08Te is one of the greatest reported for magnetic topological materials. The ferromagnetic ordering with perpendicular magnetic anisotropy, complemented by the inception of the anomalous Hall effect in the Sn1-xMnxTe layers for a thickness commensurate with the decay length of the top and bottom surface states, points at Sn1-xMnxTe Te as a preferential platform for the realization of QAH states in ferromagnetic TCIs.