Publications database

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. [...]

Unravelling emergent excitations and exotic quasiparticles in frustrated and topological quantum magnets represents a tremendous challenge experimentally, since the relevant inelastic scattering signals are very weak, often very broad in Q-space, and may be highly anisotropic in spin-space or strongly bond-direction dependent. A dedicated cold-neutron TOF spectrometer that combines with a new-generation wide-angle polarisation analysis (WAPA) can meet this challenge. [...]

The science community faces a challenging situation to maintain sustainable research with neutron methods at the moment. While neutron scattering is an indispensable microscopic probe for the investigations of magnetic order and spin excitations, there are complementary techniques at the large-scale facilities that are also suitable for magnetism research, such as element-specific magnetic resonant X-ray scattering at the synchrotron radiation facilities, and muon spectroscopy at the muon facilities. [...]

Magnetic topological quantum materials, such as magnetic Dirac and Weyl semimetals, andintrinsic magnetic topological insulators, in which topologically non-trivial band structures,magnetism and electronic correlation effects can be intertwined, have recently emerged as anexciting platform to explore exotic states and novel functionalities. As a unique microscopicprobe for magnetism, neutron scattering is ideally suited for the investigations of magneticcorrelations over a wide range of length and time scales in these novel quantum materials. [...]

Magnetic topological kagome metals, in which topologically non-trivial band structures, magnetism and electronic correlation effects can often be intertwined, have recently emerged as an exciting platform to explore exotic states and novel functionalities. In this talk, I will mainly present our recent single-crystal neutron diffraction studies of complex magnetic orders in several archetypical magnetic kagome metals, including the realization of flat-band engineered spin-density wave in the magnetic Weyl semimetal Mn$_3$Sn [1], as well as the observations of various field-induced magnetic phases that give rise to the emergent topological Hall effect in the magnetic kagome metal RMn$_6$Sn$_6$ [2].We thank Xiao Wang, Fengfeng Zhu, Yishui Zhou as well as many other co-workers and collaborators for their contributions.[1] X. [...]

The topic of data storage, traceability, and data use and reuse in the years following experiments is becoming an important topic in Europe and across the world. Many scientific communities are striving to create open data by the FAIR principles. [...]

In quantum magnetic materials, ordered phases induced by an applied magnetic field can be described as the Bose-Einstein condensation (BEC) of magnon excitations. In the strongly frustrated system SrCu2(BO3)2, no clear magnon BEC could be observed, pointing to an alternative mechanism, but the high fields required to probe this physics have remained a barrier to detailed investigation. [...]