Rao, Sumathi and Sen, Diptiman (1996) Semiclassical and field theoretic studies of Heisenberg antiferromagnetic chains with frustration and dimerization. [Preprint]
The Heisenberg antiferromagnetic spin chain with both dimerization and frustration is studied. The classical ground state has three phases (a Neel phase, a spiral phase and a colinear phase), around which a planar spin-wave analysis is performed. In each phase, we discuss a non linear sigma model field theory describing the low energy excitations. A renormalization group analysis of the SO(3) matrix-valued field theory of the spiral phase leads to the conclusion that the theory becomes $SO(3) \times SO(3)$ and Lorentz invariant at long distances. This theory is analytically known to have a massive spin-1/2 excitation. We also show that $Z_2 ~$ solitons in the field theory lead to a double degeneracy in the spectrum for half-integer spins.
|Additional Information:||J.Phys.Condens.Matter 9 (1997) 1831-1839|
|Department/Centre:||Division of Physical & Mathematical Sciences > Centre for Theoretical Studies|
|Date Deposited:||13 Aug 2004|
|Last Modified:||19 Sep 2010 04:13|
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