Spin-1 chain with spin- \frac{1}{2} excitations in the bulk

Sen, Diptiman and Surendran, Naveen (2007) Spin-1 chain with spin- \frac{1}{2} excitations in the bulk. In: Physical Review B: Condensed Matter and Materials Physics, 75 (10). pp. 104411-1.

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Abstract

We present a spin-1 chain with a Hamiltonian which has three exactly solvable ground states. Two of these are fully dimerized, analogous to the Majumdar-Ghosh MG states of a spin-\frac{1}{2}\ chain, while the third is of the Affleck-Kennedy-Lieb-Tasaki (AKLT) type.We use variational and numerical methods to study the low-energy excitations which interpolate between these ground states in different ways. In particular, there is a spin-excitation which interpolates between the MG and AKLT ground states; this is the lowest excitation of the system and it has a surprisingly small gap. We discuss generalizations of our model of spin fractionalization to higher spin chains and higher dimensions.

Item Type:	Journal Article
Publication:	Physical Review B: Condensed Matter and Materials Physics
Publisher:	American Physical Society
Additional Information:	Copyright of this article belongs to American Physical Society.
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	25 Jul 2008
Last Modified:	19 Sep 2010 04:48
URI:	http://eprints.iisc.ac.in/id/eprint/15235

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