Spin dynamics of hole-doped
Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional
de Energía Atómica, 8400 S.C. de Bariloche, Argentina
Accepted: 13 May 1998
Starting from a multiband Hamiltonian containing the relevant Ni and O orbitals, we derive an effective Hamiltonian Heff for the low-energy physics of doped For hole doping, Heff describes O fermions interacting with S=1 Ni spins in a chain, and cannot be further reduced to a simple one-band model. Using numerical techniques, we obtain a dynamical spin structure factor with weight inside the Haldane gap. The nature of these low-energy excitations is identified and the emerging physical picture is consistent with most of the experimental information on .
PACS: 75.10.Jm – Quantized spin models / 75.25.+z – Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.) / 75.50.Lk – Spin glasses and other random magnets
© EDP Sciences, 1998