SPICE Workshop on Non-equilibrium Quantum Materials Design, June 27th - 29th 2023
Jiun-Haw Chu
Weyl semimetals (WSMs) are three-dimensional topological materials that exhibit fascinating properties due to the presence of Weyl nodes in their band structure, including the chiral anomaly, Fermi arcs, and an intrinsic anomalous Hall effect. However, existing WSMs discovered so far often possess multiple pairs of Weyl nodes, posing a challenge in disentangling the contributions to transport phenomena from different energy bands and mechanisms. To overcome this challenge, we have identified field-induced ferromagnetic MnBi2-xSbxTe4 as an ideal type-II WSM with a single pair of Weyl nodes. In this talk, I will discuss how we resolved the evolution of Fermi-surface sections as the Fermi level is tuned across the charge neutrality point by employing a combination of quantum oscillations and high-field Hall measurements. I will also discuss the discovery of a singular, heartbeat-like behavior in the anomalous Hall conductivity as the Fermi level is tuned across the Weyl nodes, a unique feature previously predicted theoretically for a type-II WSM. Our findings establish MnBi2-xSbxTe4 as an ideal and tunable platform for further investigation into Weyl physics.