Properties of the t1 − t2 one-dimensional Hubbard model at finite temperature

The one-dimensional t1 − t2 half-filled Hubbard model is considered at finite temperatures T within a dynamical cluster approximation (DCA) with Nc = 24 in combination with a semiclassical approximation (SCA) impurity solver. The SCA approach accounts for long-range spatial fluctuations, where exact numerical impurity solvers can not capture due to computational expense, even though dynamical fluctuations are freezing. Therefore, it can consider both frequency- and momentum-resolved physical properties beyond the DCA with small cluster in combination with exact impurity solvers. By the computation of the static spin-spin correlation, the density of states, and the double occupancy, we examine the description of the frustrated one-dimensional systems at finite T within given approximations. We confirm not only the interaction-driven metal-insulator transition in the regions of t2/t1 > 0.5, but also the commensurate-incommensurate transition by tunning t2/t1 in the strong interaction region. We also observe finite T-driven metal-insulator transition.