Topological insulators and topological semimetals are both new classes of quantum materials, which are characterized by surface states induced by the topology of the bulk band structure. We have been working on predicting realistic materials for exotic topological phases and investigating their unique properties that can be measured by experiments, such as surface state spectra, quasiparticle interference and magneto-transport phenomena.
The Berry phase of the electronic wave function has a profound effect on material properties and is responsible for many important phenomena. Assisted by the development of ab initio calculations, we develop computational tools based on the Berry phase, anticipate and interpret interesting properties of real materials, for example, the surface Fermi arcs, anomalous Hall effect, spin Hall effect and optical properties.
Ab initio Materials Design
The ab initio computational methods based on the density-functional theory have been well developed in the past decades and demonstrated remarkable prediction power especially for predicting topological materials recently. With these computational tools, we aim to design materials for required physical properties, which is commonly supported by the insightful knowledge of chemistry.