Highly Tunable Moiré Superlattice Potentials in Twisted Hexagonal Boron Nitrides

초록

Moir & eacute; superlattice of twisted hexagonal boron nitride (hBN) has emerged as an advanced atomically thin van der Waals interfacial ferroelectricity platform. Nanoscale periodic ferroelectric moir & eacute; potentials in twisted hBN allow the hosting of remote Coulomb superlattice potentials to adjacent 2D materials. Therefore, the new strategies for engineering moir & eacute; length, angle, and potential strength are essential for developing programmable quantum materials. Here, it demonstrates the realization of twisted hBN-based moir & eacute; superlattice platforms and visualizes the moir & eacute; domains and ferroelectric properties using Kelvin probe force microscopy (KPFM). Also, the regular moir & eacute; superlattice in the large area is reported. It offers the possibility to reproduce uniform moir & eacute; structures with precise control piezo stage stacking and heat annealing. It demonstrates cumulative multi-ferroelectric polarization and multi-level domains with multiple angle mismatched interfaces. Additionally, it observes the quasi-1D anisotropic moir & eacute; domains and show the highest resolution analysis of the local built-in strain between adjacent hBN layers compared to the conventional methods. Furthermore, in-situ manipulation of moir & eacute; potential is demonstrated using femtosecond pulse laser, which results in the optical phonon-induced atomic displacement at the hBN moir & eacute; interfaces. The results pave the way to develop precisely programmable moir & eacute; superlattice platforms and investigate strongly correlated physics.

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