Magnetic Weyl nodal ring states and Landau quantization in square-net magnets

Magnetic topological semimetals (TSMs) have been the source of many new discoveries in recent years. Among the magnetic TSMs, the Weyl nodal line semimetals are probably the least experimentally studied due to the limited materials that are avaliable. To date, the only magnetic compound that has been identified to host Weyl nodal ring states with spectroscopic evidence is the Heusler alloy Co2MnGa, which has led to fruitful research results, enabling the discovery of the drumhead surface bands, giant anomalous Nernst effect, and more recently the linked-loop quantum state. In spite of these achievements, Landau quantization of the Weyl nodal line states and their associated magnetotransport properties remain largely unexplored. In this talk, I will introduce a new magnetic Weyl nodal line semimetal with a layered square-net structure motif, featuring the Weyl nodal ring states in the close vicinity of the Fermi level. I will go through the design strategy, and the detailed experimental verification including angle-resolved photoemission spectroscopy (ARPES) and quantum oscillation measurements. In this talk, the field tunable topological phase transition and the exotic magneto-transport properties in the Landau quantized regime will also be discussed.