# Colloquium (2022.11.25.fri 16:00)

**제목 : Visualizing the Fractional Topological Order : From Fractional Chern Insulators to the Tao-Thouless State**

**연사 : 박 권 박사(고등과학원)**

**Visualizing the Fractional Topological Order**

**: From Fractional Chern Insulators to the Tao-Thouless State**Kwon Park Strong correlation and topology are two main pillars of modern physics, which can be bridged by fractional quantum Hall states and their lattice analogues known as fractional Chern insulators. A particularly pressing question for fractional Chern insulators is if there exists a lattice analogue of the Laughlin state in the 1/3-filled Chern flat band dubbed as the Chern-Laughlin state and, if so, how to detect it experimentally. In this talk, I will show that the existence of an adiabatic path from the 1/3-filled fractional Chern insulator to the Tao-Thouless state, i.e., the root partition state of the Laughlin state in the thin torus limit, can serve as an effective order parameter for the precise identification of the Chern-Laughlin state. More importantly, unless the electron-electron interaction is strictly of the nearest-neighbor form, the Tao-Thouless state can be actually detected experimentally in an incommensurate double-walled carbon nanotube made out of the magic-angle twisted bilayer graphene, visualizing the fractional topological order. This method can be extended to various other fractional Chern insulators corresponding to both Abelian and non-Abelian fractional quantum Hall states.