Talk (non-conference) (Invited)

FZJ-2025-00042

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Neutron scattering on magnetic topological materials

Su, Y.FZJ*

2022

Abstract: Magnetic topological materials, such as magnetic Dirac and Weyl semimetals, and intrinsic magnetic topological insulators, in which topologically non-trivial band structures, magnetism and electronic correlation effects can be intertwined, have recently emerged as an exciting platform to explore exotic states and novel functionalities. As a unique microscopic probe for magnetism, neutron scattering is ideally suited for the investigations of magnetic correlations over a wide range of length and time scales in these emergent quantum materials. In this talk, I will present our recent neutron scattering studies of magnetic topological materials, with the main aim to demonstrate the fascinating interplay between topology, magnetism and electronic correlation. In the Dirac semimetal EuMnBi$_2$, the evidence for the possible impact of magnetism on Dirac fermions is obtained via a detailed neutron diffraction study of the spin-flop transition [1]. In the two-dimensional van der Waals honeycomb ferromagnets CrSiTe$_3$ and CrGeTe$_3$, the exotic topological magnon insulators, the bosonic analogue of topological insulators, have been experimentally realized based on our inelastic neutron scattering study and theoretical analysis of spin-wave excitations [2]. Furthermore, in the magnetic Weyl semimetal Mn$_3$Sn, an unusual magnetic phase transition that is driven by emergent many-body effects can be revealed via our combined polarised neutron scattering study and band-structure calculations [3].[1] F. Zhu, et al., Phys. Rev. Research 2, 043100 (2020).[2] F. Zhu, et al., Sci. Adv. 7, eabi7532 (2021).[3] X. Wang, et al., (submitted).

Keyword(s): Magnetic Materials (1st) ; Information and Communication (1st) ; Magnetism (2nd) ; Condensed Matter Physics (2nd)

---

Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)

Experiment(s):

1. DNS: Diffuse scattering neutron time of flight spectrometer (NL6S)
2. HEiDi: Single crystal diffractometer on hot source (SR9b)
3. PUMA: Thermal three axes spectrometer (SR7)
4. ILL-IN12: Cold neutron 3-axis spectrometer
5. Measurement at external facility

---