Fig. 2. C-paired SVL in monolayer V₂Se₂O.

a Two sublattice A and B in monolayer V₂Se₂O is related by a diagonal mirror symmetry $M_{\varphi }$. b 2D Néel antiferromagnetic (AFM) order with local magnetic moments located at V1 and V2 atoms with polarization labeled by black arrows. c Monolayer V₂Se₂O is a semiconductor with gap ~0.7 eV. Red (blue) color is for spin-up (down). d The energy contour taken at 0.2 eV below the valance band maximum with possible typical inter-valley and intra-valley scattering vectors ${\mathbf{q}}_{1,2}$ and ${\mathbf{q}}_{3,4}$. e, f Calculated quasi-particle interference (QPI) patterns with and without considering the spin flipping. Due to SVL and weak SOC, inter-valley scattering is strongly suppressed. The existence of AFM order and C-paired SVL can be easily verified by the absence of scattering patterns around the corner in QPI image.