Intriguing Magnetism of the Topological Kagome Magnet TbMn₆Sn₆

Magnetic topological phases of quantum matter are an emerging frontier in physics and material science [1-3], of which kagome magnets appear as a highly promising platform. Here, we explore magnetic correlations in the recently identified topological kagome system TbMn₆Sn₆ using muon spin rotation, combined with local field analysis and neutron diffraction [1]. Our studies identify an out-of-plane ferrimagnetic structure with slow magnetic fluctuations which exhibit a critical slowing down below T^*_C1 ≅ 120 K and finally freeze into static patches with ideal out-of-plane order below T_C1 ≅ 20 K. The appearance of the static patches sets in at a similar temperature as the topological transport behaviors. We further show that a hydrostatic pressure of 2.1 GPa stabilizes the static out-of-plane topological ferrimagnetic ground state in the whole volume of the sample. Therefore the exciting perspective arises of a magnetically-induced topological system whose magnetism can be controlled through external control parameters. The present results [1] will stimulate theoretical investigations to obtain a microscopic understanding of the relation between the low-temperature volume-wise magnetic evolution of the static c-axis ferrimagnetic patches and the topological electronic properties in TbMn₆Sn₆.



[1] C. Mielke III et al., Comm. Phys. 5, 107 (2022).

[2] J.-X. Yin et al., Nature 583, 533-536 (2020).

[3] N.J. Ghimire and I.I. Mazin, Nature Materials 19, 137-138 (2020).