Research

The goals and research thrusts of CATS are interwoven.  For example, the discovery of new topological states of matter may be discovered in bulk single crystals (RT-1) or heterostructure assemblies (RT-2), or under non-equilibrium conditions in applied fields (RT-3).  In addition, the development of emergent functionality in layered heterostructures of 2D materials (RT- 2) requires the discovery of new, exfoliatable topological semimetals (TSMs) (RT-1).  All research thrusts in CATS will exploit premier characterization capabilities and the ability to apply static and time-dependent external fields to manipulate and switch TSM properties. CATS will combine fundamental theory and insight with first-principles electronic structure calculations; results from such calculations for relevant materials and heterostructures will be used to construct response functions, magnetotransport models, and non-equilibrium theories.

Research Thrust 1: Predict, discover, and understand the underlying mechanisms of new magnetic TSMs

The central goal of RT-1 is to discover new TSMs and understand their properties. Mastering weakly coupled magnetic Weyl semimetals will provide the foundation to understand more strongly coupled systems. It also provides the first step in our understanding a much broader class of TSMs, such as nodal line semimetals.

Research Thrust 2: Discover and control novel quantum states and functionality in thin films and heterostructures

The central goal of RT-2 is to create, control, and manipulate new topological materials using thin films, monolayers, and carefully designed hetero- and nanostructures based on TSM materials. Not only are heterostructures required for many potential applications, such as novel spintronic and optoelectronic devices, but they also allow for control and manipulation methods, such as gating fields, confinement, interfaces, and proximity effects, that are not possible with bulk materials.

Research Thrust 3: Investigate the dynamical manipulation of topological states

In RT-3, we will identify optical signatures of TSM states in materials produced by RT-1 and RT-2 and develop dynamic approaches to control spin and charge transport, electro-optic response, and topological state coherence in TSM.