Spin dimer modelS. Rachel
Institut für Theorie der Kondensierten Materie, Universität Karlsruhe Postfach 6980, 76128 Karlsruhe, Germany, EU
received 3 February 2009; accepted in final form 9 April 2009; published May 2009
published online 14 May 2009
We present a parent Hamiltonian for weakly dimerized valence bond solid states for arbitrary half-integral S. While the model reduces for S=1/2 to the Majumdar-Ghosh Hamiltonian, we discuss this model and its properties for S=3/2. Its degenerate ground state is the most popular toy model state for discussing dimerization in spin 3/2 chains. In particular, it describes the impurity-induced dimer phase in Cr8Ni as proposed recently. We point out that the explicit construction of the Hamiltonian and its main features apply to arbitrary half-integral spin S.
75.10.Pq - Spin chain models.
75.10.Dg - Crystal-field theory and spin Hamiltonians.
75.10.Jm - Quantized spin models.
© EPLA 2009