Europhys. Lett., 63 (4) , pp. 505-511 (2003)
Spin-one bosons in low-dimensional Mott insulating statesF. Zhou
ITP, Utrecht University, Minnaert building - Leuvenlaan 4 3584 CE Utrecht, The Netherlands
(Received 14 April 2003; accepted in final form 13 June 2003)
We analyze the strong-coupling limit of spin-one bosons in low-dimensional lattices. In one-dimensional lattices, for an odd number of bosons per site ( N0=2k+1), the ground state is a dimerized-valence-bond crystal with a twofold degeneracy; the low-lying elementary spin excitations carry spin-one. For an even number of bosons per site ( N0=2k), the ground state is a nondegenerate spin singlet Mott state. We also argue that for square lattices in a quantum spin disordered limit, ground states should be dimerized-valence-bond crystals for an odd integer N0. Finally, we briefly report results on exotic states for non-integer numbers of bosons per site in one-dimensional lattices.
05.30.Jp - Boson systems.
05.50.+q - Lattice theory and statistics (Ising, Potts, etc.).
75.10.Jm - Quantized spin models.
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