Tuning the topological and magnetic properties of TIs

We studied solid solutions with a general formula GexMn1-xBi2Te4 between two TIs, magnetic MnBi2Te4 and nonmagnetic GeBi2Te4. We observed linear x-dependent magnetic properties and topological phase transitions (TPTs) between topologically nontrivial phases and a Dirac semimetal state.

  Frolov et al., Commun. Phys. 7, 180 (2024).



Using experimental and theoretical methods, we studied solid solutions GexMn1-xBi2Te4 between two isostructural TIs, magnetic MnBi2Te4 and nonmagnetic GeBi2Te4. We observed linear x-dependent magnetic properties, composition-independent pairwise exchange interactions, and topological phase transitions (TPTs) between topologically nontrivial phases and the semimetal state. The TPTs are driven purely by the variation of orbital contributions. The gapless state observed at x = 0.42 closely resembles a Dirac semimetal above the Néel temperature and shows a magnetic gap below, which is clearly visible in raw photoemission data. The observed behavior

 demonstrates an ability to precisely control topological and magnetic properties of TIs.

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Magnetic Dirac semimetal state of (Mn,Ge)Bi2Te4
A.S. Frolov, D.Yu. Usachov, A.V. Tarasov, A.V. Fedorov, K.A. Bokai, I. Klimovskikh, V.S. Stolyarov, A.I. Sergeev, A.N. Lavrov, V.A. Golyashov, O.E. Tereshchenko, G. Di Santo, L. Petaccia, O.J. Clark, J. Sanchez-Barriga, L.V. Yashina,
Commun. Phys. 7, 180 (2024).
doi: 10.1038/s42005-024-01675-w

Last Updated on Monday, 30 December 2024 19:19