Localized singlets and ferromagnetic fluctuations in the dilute magnetic topological insulator Sn0.95Mn0.05Te

Article

关键词: TRANSITION;    MN;    REALIZATION;    CRYSTALS;   

DOI  :  10.1103/PhysRevB.101.140406

来源: SCIE

【 摘 要 】

The development of long-range ferromagnetic (FM) order in dilute magnetic topological insulators can induce dissipationless electronic surface transport via the quantum anomalous Hall effect. We measure the magnetic excitations in a prototypical magnetic topological crystalline insulator, Sn0.95Mn0.05Te, using inelastic neutron scattering. Neutron diffraction and magnetization data indicate that our Sn0.95Mn0.05Te sample has no FM long-range order above a temperature of 2 K. However, we observe slow, collective FM fluctuations (< 70 mu eV), indicating proximity to FM order. We also find a series of sharp peaks originating from local excitations of antiferromagnetically (AF) coupled and isolated Mn-Mn dimers with J(AF) = 460 mu eV. The simultaneous presence of collective and localized components in the magnetic spectra highlight different roles for substituted Mn ions, with competition between FM order and the formation of AF-coupled Mn-Mn dimers.

【 授权许可】

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