Influence of the modulated hopping on the one-dimensional interacting electron system

• We study the extension of 1D Hubbard model by modulating the hopping term.
• We study the effect of the induced interactions on topology of phase diagram of the model.
• In the absence of V, an insulator–metal transition takes place.
• In the presence of U and V, the induced three-body interaction breaks an accident symmetry.
• We present a theoretical argument for the occurrence of the TS and BSDW phases.

By introducing a modulation parameter (ξ), we study the one-dimensional correlated system with modulated hopping, on-site (U) and nearest-neighbor (V  ) repulsions in the weak-coupling regime. The induced three-body attraction changes topology of the conventional phase diagram. Besides the usual CDW and SDW phases, a BSDW phase exists for |U−2V|<8tξ2/π|U−2V|<8tξ2/π. In the absence of V  , an insulator–metal transition takes place, and the TS phase is realized for ξ>πU/8t. Phenomenologically, the general quantum phase diagram including insulating and superconducting phases is discussed.