Principal Investigator Nuh Gedik
The topological insulator is a fundamentally new phase of electronic matter that defies the conventional Landau symmetry breaking paradigm. They are realized in electrically insulating materials whose band gap is induced by large spin-orbit coupling. One of the unique and defining characteristics of a topological insulator is the presence of spin-polarized metallic surface states that obey a light-like dispersion relation.
These surface states have recently been proposed to be a platform for realizing exotic particles such as Majorana fermions as well as realizing optical and spintronic devices with new functionalities.
The Lab is investigating the optical properties of the surface states of topological insulators. This is a challenging task because the surface states are confined to an ultra narrow nanometer region of the surface whereas probe photons penetrate much deeper into the material. Therefore the surface state contribution to any optical signal is typically only a tiny addition to a predominantly bulk response.