Abstract
Effects of the intrachain electron-electron umklapp process and theinterchain one-particle hopping, t⊥, in a weakly coupledhalf-filled chain system have been studied, based on the perturbativerenormalization-group approach.By solving the scaling equations, we found that the intrachain umklappprocess strongly suppresses an interchain one-particle process and causes a finite critical value for t⊥, t⊥c. Fort⊥⊥ c, as the temperature decreases, the system undergoes a phase transition into an antiferromagnetic long-range-ordered phase at a transitiontemperature TN which increases with the increasing t⊥. On the other hand, for t⊥>t⊥ c, the system undergoes acrossover to the Fermi liquid phasewhere the interchain coherent propagation of quasi-particles occurs.
