HOLE MOTION IN ONE-DIMENSIONAL T-J-J' MODEL

We examined the one-dimensional t-J-J’ model by numerical diagonalization. This model describes electrons with infinite on-site repulsion, nearest-neighbor transfer t, exchange interaction J and, further, next-nearest-neighbor exchange interaction J’. In the case of one hole and J’/J≳0.5, the numerical ground state consists mainly of singlet dimers like that in the no-hole case (Heisenberg spin system). The energy spectrum and hole densities for low excited states show that the hole moves as a free quasiparticle, separated from the degrees of freedom for spins. © 1990, Elsevier Science Publishers B.V. (North-Holland). All rights reserved.