Successful defence of Shuo-Ying Yang
Congratulations to Shuo-Ying Yang!
Title: "In search of extraordinary Hall effects in topological semimetals"
Following the discovery of topological insulators, the development of topological band theory has led to the prediction and discovery of various topological semimetals. Topologically non-trivial materials have not only introduced novel fundamental physical concepts and properties, but have also provided new routes to developing technological applications in nanoelectronics, spintronics, and topological quantum computing [2–4]. Investigating novel electronic transport phenomena in these solids and comparing with topologically trivial materials has become an important frontier in condensed matter physics today. This thesis mainly focuses on the electrical transport behaviors of novel topological semimetals; in particular, the anomalous Hall effect (AHE) where itinerant electrons acquire a transverse velocity without an applied magnetic field, and the PHE where a Hall voltage appears when the applied magnetic field and electrical field are co-planar. Three material systems will be discussed, including the trivial semimetal, bismuth, the ferromagnetic Weyl semimetal, Co3Sn2S2, and the magnetically frustrated Dirac semimetal candidate, KV3Sb5.