Fig. 3. Tip-induced control of interlayer coupling strength and simulated electronic bandstructures.

a Schematic illustration of the local tip control of the interlayer distance d_I in a WSe₂/Mo_0.5W_0.5Se₂ heterobilayer. b TEPL spectra before (top) and after (bottom) pressing the heterobilayer with GPa scale tip-pressure, which causes significant modifications in electronic bandstructure. c Electronic bandstructure calculated via DFT for a WSe₂/Mo_0.5 W_0.5 Se₂ heterobilayer (gray) at equilibrium interlayer distance d_I = 6.45 Å, with the highest valence and lowest conduction bands highlighted in blue; the direct K-K transition is indicated with green arrow; inset shows high-symmetry points in the hexagonal Brillouin zone. The Fermi energy E_F is defined as an averaged energy of the conduction band minimum and the valence band maximum. d Calculated energy shift for the K-K transition in a WSe₂/Mo_0.5 W_0.5 Se₂ heterobilayer as a function of d_I (green circles) and corresponding linear fit (green line), together with the experimentally measured tip-induced IX shift (black arrow)