One-dimensional repulsive Hubbard model with mass imbalance: Orders and filling anomaly

We investigate the phase diagram of the one-dimensional repulsive Hubbard model with mass imbalance. Using DMRG, we show that this model has a triplet paired phase (dubbed pi SG) at generic fillings, consistent with previous theoretical analysis. We study the topological aspect of pi SG phase, determining long-range string orders and the filling anomaly which refers to the relation among the single-particle gap, inversion symmetry, and filling imbalance for open chains. We also find, using DMRG, that at 1/3 filling, commensurate effects lead to two additional phases: A crystal phase and a trion phase; we construct a description of these phases using Tomonaga-Luttinger liquid theory.

Automated summary

In the investigation of the phase diagram of the one-dimensional repulsive Hubbard model with mass imbalance, it was found that a triplet paired phase and two additional phases (crystal phase and trion phase) can occur. These phases were characterized using the Tomonaga-Luttinger liquid theory.