PHYSICS: STUDIES FROM YEREVAN STATE UNIVERSITY IN THE AREA OF PHYSICS DESCRIBED
Science Letter
September 16, 2008
According to a study from Yerevan, Armenia, "The Lieb-Mattis theorem
is generalized to an antiferromagnetic spin-ladder model with four-spin
cyclic exchange interaction."
"We prove that for J>2 K, the antiferromagnetic ordering of energy
levels takes place separately in two sectors, which remain symmetric
and antisymmetric under the reflection with respect to the longitudinal
axis of the ladder. We prove also that at the self-dual point J=2 K,
the Lieb-Mattis rule holds in the sectors with fixed number of rung
singlets," wrote T. Hakobyan and colleagues, Yerevan State University
(see also Physics).
The researchers concluded: "In both cases, it agrees with the similar
rule for Haldane chain with appropriate spin number."
Hakobyan and colleagues published the results of their research in
Physical Review B (Antiferromagnetic ordering of energy levels for
a spin ladder with four-spin cyclic exchange: Generalization of the
Lieb-Mattis theorem. Physical Review B, 2008;78(1):2407).
For additional information, contact T. Hakobyan, Yerevan State
University, 1 Alex Manoogian, Yerevan 375025, Armenia.
The publisher of the journal Physical Review B can be contacted
at: American Physical Society, One Physics Ellipse, College Pk,
MD 20740-3844, USA.