Hole-doping effects on orthogonal-dimer spin chain Original Research Article

We study the hole-doping effects on the frustrated orthogonal-dimer spin model with linked-tetrahedra chain structure. By using the density matrix renormalization group method we discuss how the metal–insulator transition is affected by geometrical frustration. When the system is in the dimer-singlet phase, hole-doping smoothly drives the system to a metallic phase. In contrast when the system is in the plaquette-singlet phase strong frustration induces the first-order transition to a metallic phase upon hole-doping which is characterized by the discontinuity in the electron density. We compute the spin correlation function to clarify the origin of the first-order phase transition.