Inelastic neutron scattering experiments reveal that magnetism in stoichiometric and lightly doped magnetic topological insulators in the Sb2Te3-MnSb2Te4 family is controlled by universal interactions between magnetic defects.
Magnetic order in topological insulators unlocks dissipationless transport and quantized magnetoelectric responses. This discovery shows how competing ferromagnetic and antiferromagnetic interactions between defects control the magnetic state of topological insulators, paving the way for defect engineering of magnetic topological materials.
- Inelastic neutron scattering experiments on (Sb1.94Mn0.06)Te3 single-crystals were performed at the Cold Neutron Chopper Spectrometer at the Spallation Neutron Source.
- Magnetization, transmission electron microscopy, and energy dispersive spectroscopy measurements confirm high-quality specimens.
- Density-functional theory calculations of the pairwise magnetic interactions reinforce the experimental data.
F. Islam, Y. Lee, D. M. Pajerowski, J. Oh, W. Tian, L. Zhou, J.-Q.Yan, L. Ke, R. J. McQueeney, D. Vaknin. Adv. Mater. 2209951 (2023).DOI: 10.1002/adma.202209951