Rao, S and Sen, D (1997) Field theories for frustrated antiferromagnetic spin chains. In: Journal Of Physics-Condensed Matter, 9 (8). pp. 1831-1839.
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We study the antiferromagnetic spin chain with both dimerization and frustration. The classical ground state has three phases, a Neel phase, a spiral phase and a collinear phase, which we study through a nonlinear sigma-model approach. In the spiral phase, the held theory becomes SO(3) x SO(3) and Lorentz invariant at long distances, a model which is exactly solvable. The low-energy spectrum is doubly degenerate with massive 'elementary' spin-1/2 particles and 'two-particle' triplet and singlet physical excitations. The field theory also supports Z(2) solitons which lead to a double degeneracy of the ground state for half-integer spins (when there is no dimerization).
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Institute of Physics.|
|Department/Centre:||Division of Physical & Mathematical Sciences > Centre for Theoretical Studies|
|Date Deposited:||21 Jul 2009 10:48|
|Last Modified:||19 Sep 2010 05:26|
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