Fig. 2: Domain evolution in double-gated marginally twisted MoS₂ bilayers.

a–c, BSECCI image of a triangular network of small domains undergoes expansion/contraction as a function of applied electric field (\(D/\varepsilon _0 = 0\; {{\mathrm{Vnm}}^{-1}}\;({\mathrm{a}}), 1.4\; {{\mathrm{Vnm}}^{-1}}\;({{\mathrm{b}}}), -1.4\; {{\mathrm{Vnm}}^{-1}}\;({\mathrm{c}})\)) overlaid with the analytical model equations (2) and (3), yellow lines. Scale bars, 200 nm. d–f, BSECCI image of larger domains, where the partial dislocations that constitute the domain walls merge near the nodes and the energetically disadvantaged domain collapses locally into a PSD at the applied electric field values of 1.4 Vnm⁻¹ (e) and −1.4 V nm⁻¹ (f). Micrographs are presented in their chronological order and the contrast is seen to deteriorate due to beam-induced surface contamination. Scale bars are 200 nm. g–i, Polarization maps for different values of scaling parameter computed using mesoscale relaxation of the bilayer lattice (Supplementary Information) and compared with the analytical model (yellow curves) of the scaled domain evolution given by equations (2) and (3). As the domain walls consist of two partial dislocations with Burgers vectors \(\frac{a}{{\sqrt 3 }}\left( {1,0} \right)\) and \(\frac{a}{{\sqrt 3 }}\left( {\frac{1}{2},\frac{{\sqrt 3 }}{2}} \right)\), line defects observed can be assigned to a PSD with Burgers vector \(a\left( {\frac{{\sqrt 3 }}{2},\frac{1}{2}} \right)\).