Fermionic Representation of a Spin S chain Using subalgebra of SU(2S+1)

B. Basu-Mallick, Nilanjan Bondyopadhaya, Kazuhiro Hikami +1 more

Mikhail N. Kiselev, Heiko Feldmann, R. Oppermann

Y. Tsue, Constança Providência, João da Providência +1 more

Standing on the results for the minimum weight states obtained in the previous paper (I), an idea how to construct the linearly independent basis is proposed for the su(n)-Lipkin model. This idea starts in setting up m independent su(2)-subalgebras in the cases with n=2m and n=2m+1 (m=2,3,4,...). The original representation is re-formed in terms of the spherical tensors for the su(n)-generators built under the su(2)-subalgebras. Through this re-formation, the su(m)-subalgebra can be found. For constructing the linearly independent basis, not only the su(2)-algebras but also the su(m)-subalgebra play a central role. Some concrete results in the cases with n=2, 3, 4 and 5 are presented.

Yang Xian

After a proper definition of the dimerization order parameter for a spins system, I show that this order parameter in the SU (n) (n=2S+ 1 ) antiferromagnetic chains (or equivalently the SU(2) spins chains with Hamiltonians which project out singlet states) is, in the thermodynamic limit, directly proportional to the staggered-magnetization in the corresponding spin-½ XXZ chains which had already been mapped onto the SU (n) chains

Alan Macfarlane

Dietrich E. Wolf, J. Zittartz