Ground states and photoemission spectra in a magnetic frustrated organic chainW. Z. Wang1 and K. L. Yao2
1 Department of Physics, Wuhan University - Wuhan 430072, PRC
2 Department of Physics, Huazhong University of Science and Technology Wuhan 430072, PRC
received 3 May 2004; accepted in final form 14 January 2005
published online 11 February 2005
The magnetic frustration in a quasi-one-dimensional organic polymer is studied. The results show that if the frustrating hopping is turned on, three ground-state phases are found: a ferrimagnetic phase, two singlet phases. Two nearly degenerate states with one sublattice forming spin singlet are also discussed. The difference of phase diagrams between the present Hubbard model and the Heisenberg model results from the appearance of charge order in the Hubbard model. Due to the frustration, the particle-hole symmetry in the single-particle spectra is destroyed. The relation between the spectral functions and the spin configurations are investigated for different phases.
71.27.+a - Strongly correlated electron systems; heavy fermions.
75.30.Fv - Spin-density waves.
71.10.Fd - Lattice fermion models (Hubbard model, etc.).
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