Taehyung Kim
Kyung Hee University, Seoul, Republic of Korea _______________________________________
Twisted hexagonal boron nitride (hBN) heterostructures offer exceptional advantages in nanoscale ferroelectric control, enabling tunable moiré potentials and strain-modulated interfacial phenomena. This work demonstrates the direct visualization of strain-induced moiré superlattices and twirled domain architectures at interfacial bubbles via Kelvin probe force microscopy (KPFM). Local strain gradients generated by bubble topography correlate with reconstructed moiré patterns, revealing twirled alternating AB/BA ferroelectric domains and saddle-point-polarized regions at the center. KPFM maps further resolve twisted superlattice symmetries disrupted by anisotropic strain, manifesting as elongated triangular domains and quasi-1D striped polar textures. Also, the interplay between twist-angle-dependent moiré periodicity and strain-driven atomic reconstruction enables deterministic engineering of multilevel polarization states. These findings establish twisted hBN as a versatile platform for tailoring electromechanical responses and optoelectronic functionalities through strain-coupled moiré engineering.
Email: bypass99@khu.ac.kr