Variational study of the interacting spinless Su-Schrieffer-Heeger model

摘要: We study the phase diagram and total polarization distribution of Su-Schrieffer-Heeger model with nearest neighbor interaction in one dimension at half-filling. To obtain ground state wave-function, we extend Baeriswyl variational wave function to account for alternating hopping parameters. The energies functions compare well exact diagonalization results. For case uniform all bonds, where it is known that an ideal conductor insulator transition takes place finite interaction, also find a strength somewhat lower than value. Fermi sea. whole parameter range shows resemblance Kane-Mele-Hubbard model. calculate gauge invariant cumulants corresponding (Zak phase) use these reconstruct polarization. reconstructed along path space which connects two points opposite ways. In cross metallic line, other, go through only insulating states. former case, average changes discontinuously after passing while latter "walks across" smoothly from its opposite. This affairs suggests correlation acts break chiral symmetry model, same way as happens when Rice-Mele onsite potential turned on.