Speaker
Description
Intrinsic magnetic topological insulators from the MnBi₂Te₄·(Bi₂Te₃)ₙ family have garnered significant attention as versatile platforms capable of hosting a range of exotic quantum states and phenomena, including higher-order topological phases, axion electrodynamics, and the quantum anomalous Hall effect. This tunability arises from manganese–pnictogen intermixing, which is sensitive to synthesis conditions.
In this work [1], we use nuclear magnetic resonance and muon spin rotation and relaxation spectroscopy complemented by DFT calculations to explore the impact of the intermixing on the magnetic properties of (MnBi2Te4)(Bi2Te3)n and MnSb2Te4. Our findings show that Mn moments on native sites and antisites align oppositely in the ground state for (MnBi₂Te₄)(Bi₂Te₃)ₙ (n = 0, 1, 2) and MnSb₂Te₄. Moreover, in all compounds, the Mn antisite sublattice disorders at temperatures significantly below the intrinsic magnetic transition, giving rise to an intermediate phase with a uniform magnetic structure unaffected by intermixing. This phase is likely where the anticipated exotic quantum states can be observed. Our results provide a microscopic understanding of the crucial role played by Mn-Bi intermixing and offer pathways for understanding the surface gap states.
Reference
[1] M. Sahoo, I. J. Onuorah et al., Adv. Sci., 11, 34, 2402753, 2024
| ifeanyijohn.onuorah@unipr.it | |
| Funding Agency | Ministero dell'Università e della Ricerca, Finanziato dall'Unione europea (NextGenerationEu), Italia Domani è il Piano Nazionale di Ripresa e Resilienza (PNRR) italiano |
| Supervisors Name | Roberto De Renzi |
| Supervisors Email | roberto.derenzi@unipr.it |
| Did you request an Invitation Letter for a Visitors Visa Application | Yes |
