Resonant tunneling detection of atomic reconstruction in twisted bilayer WSe₂

In twisted bilayer WSe₂ (tBL-WSe₂) at low twist angles, atomic reconstruction is driven based on moiré periodicity. In this study, we perform resonant tunneling measurements and transmission electron microscopy (TEM) observations for tBL-WSe₂ samples with various twist angles θ_BL from 0° to 34°, and reveal the connection between atomic reconstruction and the resulting Γ-point band energy landscape. The resonant tunneling results consistently indicate the presence of two peak currents associated with tunneling into VB-Γ-point states of tBL-WSe₂, regardless of the twist angle. As the twist angle increases from θ_BL = 0°, the energy spacing between these peaks decreases from ~0.7 eV and stabilizes at approximately ~0.6 eV for θ_BL ≥ 6°. In comparison, the TEM observations show atomic reconstruction patterns persisting up to θ_BL ~ 5°. It is worth noting that the energy spacing of the VB-Γ-point is significantly influenced by the interlayer distance of WSe₂. Therefore, we have shown that we can detect atomic reconstruction in tBL-WSe₂ through the changes in interlayer distance, which alter the resonant tunneling behavior into the VB-Γ-point states.