Two-dimensional Topological States in Thin Films of Cadmium Arsenide

In this talk, we will discuss two-dimensional topological states in high-quality thin films of cadmium arsenide (Cd₃As₂) grown by molecular beam epitaxy. Cd₃As₂ is known to belong to a class of topological materials known as three-dimensional Dirac semimetals, but, as we will discuss in this presentation, in thin films it can be tuned between a variety of topological phases. We will discuss the evolutionof the electronic states of Cd₃As₂ films as their thickness is scaled. We also discuss a two-dimensional Weyl semimetal phase that is obtained under applied in-plane magnetic fields. We show that magnetotransport studies can distinguish between the different topological phases.