QLunch: On the construction of exponentially localized Wannier functions

Speaker: Horia Cornean from Aalborg University

Title: On the construction of exponentially localized Wannier functions

Abstract:
We will give an elementary introduction to the Wannier function theory and investigate under which conditions such functions can be constructed. We will see that the topological obstructions which might prevent the existence of exponentially localized Wannier functions in two dimensions are essentially the same as the ones encountered in connection to the classical Hairy Ball Theorem. The talk is based on joint work with Domenico Monaco (Rome).