Department of Applied Physics Research Seminar: Raquel Queiroz

Abstract

Nontrivial topology plays a crucial role in how a system behaves in the presence of impurities and crystalline defects. Topological phases are characterized by a lack of an exponentially localized Wannier representation that respects the local and crystalline symmetries of the system. In this talk, I will relate the lack of localizability to a universal structure of the real part of the local Green's function. I will show that this structure is manifested in defect-bound states with unique qualitative features, independent of the exact nature of the topological phase or which symmetry protects it. Universal defect states can provide critical cues to prove a material is in a topological phase, particularly in phases where crystalline symmetries protect the topology and the boundary states are hard to access.

Bio

Raquel Queiroz is Assistant Professor at Columbia University, and she leads the Topological Matter group at Columbia. Her group investigates quantum phenomena of condensed matter systems and are fascinated with symmetry and topology. In particular, her group explores how topology crucially influences fundamental characteristics of solid-state materials.

Zoom link: https://aalto.zoom.us/j/62052128099