Topological Mott insulator by block spin phenomenology

Abstract We investigate the relationship between topological Mott insulators and spin glasses. By first explaining the phase of spin glass on the basis of finite sized block spin concepts, we then introduce the three-dimensional insulating phase of a topological insulator with a finite bulk bandgap as the pairing of block spins comprised of many random spins with respective majority spin directions. However, the two-dimensional edge state of the topological insulator may be thought of as the pairing of triplet spins with a zero bandgap. Topological insulators can be transformed into ordinary insulators below a certain temperature. Electric field-induced transitions between normal and topological insulators are possible as explained by means of composite charges.