Local basis for interacting topological bands

by Dr Nishchhal Verma (Columbia University)

Friday 17 Jul 2026, 11:00 → 12:00 Asia/Kolkata

AG 66 and on Zoom

Topology acts as an obstruction to an exponentially localized, orthonormal, and complete basis in real space. In this talk, I will discuss various ways around this obstruction and construct a local basis set using the projected density operator. The spectrum of the operator provides a systematic way to identify local orbitals and uncover a natural hierarchy of interaction scales. This framework applies to both tight-binding and continuum models, and it offers a universal prescription for reducing the single-particle Hilbert space dimension.