Abstract
Discovering and classifying new phases is an ever-lasting theme in condensed matter. A whole new big family of phases has been found since the 1980s as well as being categorized into universality classes labelled by topological indices. Such phases are well-known to hold gapless boundary states with insulating bulk. Classification of metallic phases, on the other hand, gradually makes progress with deeper understanding of quantum anomaly in condensed matter by analogy. Among these phases the one with only half-quantized Hall conductance is predicted to stand with chiral edge current even in absence of chiral edge state, and its existence has been found experimentally. Here in this talk, I will show novel topological metallic phase as quantum anomalous Hall effect without chiral edge state based on picture from an exact solution of topological insulator thin film. We attribute the physical mechanism behind to ‘mass exchange’, which is closely related to the second Dirac band in addition to surface state.
Anyone interested is welcome to attend.