Regensburg 2022 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 30: 2D Materials 7 (joint session DS/CPP)

CPP 30.5: Vortrag

Mittwoch, 7. September 2022, 16:00–16:15, H17

Network of 1d edge channels and localized states emerging in moiré system — •Jeyong Park, Jinhong Park, and Achim Rosch — Institute of theoretical physics, University of Cologne, Germany

For the general moiré system, we theoretically study the effective Hamiltonian for single layer considering the smooth periodic moiré potential induced by other layer, which appears because of distance difference between each pair of atoms located on different layer. For moiré potential larger than tunable moiré energy scale, we find the coexistence of 1D channels and localized state in real space. The 1D channels emerge along the three 1D lines where the mass gap of single layer coming from moiré potential becomes zero, which is showing that these channels are the edge states. Localized states emerge at the crossing point of three 1d lines. We construct the toy model which describes the coexistence of these states by symmetry analysis and consider the RKKY interaction between localized states which is mediated by 1D channels by including whole spin and valley degrees of freedom. Expanding the effective action for the toy model and controlling chemical potential to suppress oscillation coming from fermi momentum gives three spin interaction S·(S× S), which can give chiral spin liquid phase. We show how the analytical result can be seen in our model numerically and propose the graphene on top of AB stacking bilayer with twist as the candidate material for realization.