Advanced Study Group: Hidden order in incommensurately stacked multilayers



Pilkyung Moon (New York University in Shanghai, China)


Moonjip Park (PCS IBS)

Youngkuk Kim (SKKU, Korea)

Jun-Won Rhim (Ajou Univ, Korea)

Nojoon Myoung (CU, Korea)

Hee Chul Park (PCS IBS)

Joung-Real Ahn (SKKU, Korea)

Heejun Yang (KAIST, Korea)

Young Woo Son (KIAS, Korea)


The weak van der Waals interaction between two-dimensional atomic layers en- ables various stacking geometries, such as various twist angles, without being restricted by the lattice commensuration obeyed by conventional 3D crystals. And such incommensurately stacked atomic layers provide a unique opportunity to couple the monolayer states of each layer with different wave vectors. In this project, we will explore the electronic structures and relevant physical properties such as optical selection rule, phonon, electron phase. We will put more emphasis on specific configurations which host quasicrystalline electronic states.

The aim of this Advanced Study Group provides the chance to share the novel ideas and to solve the problems through collaborations among the different ap- proaches. We have a plan, at first, to set up the initiative problem related to the incommensurately stacked atomic layers and then to gather the branch prob- lems through the brainstorming with all of members. There are a lot of derived phenomena by stacking 2 dimensional materials such as quasicrystal inflation pattern, multiferroic, superconductivity, and higher-order topological insulators. The grouping by overlapped topics and distinguished approaches should make synergies in collaborations. We will study the physical properties of the layered materials by topological band theory by the first principle calculation and sym- metry analysis, optical transition, electron transport, field theoretical approach including interaction and disorder, and so on. Although the works are related to the theoretical interests, most of all problems will be considered by experimental realization through advice of members in experiment. Some We expect that the on-offline hybridised meetings offer the more active and continuous coworks.