Kagome antiferromagnet : a Schwinger-boson mean-field theory study
Date of Issue2007
School of Materials Science and Engineering
The Heisenberg antiferromagnet on the kagome lattice is studied in the framework of Schwinger-boson mean-field theory. Two solutions with different symmetries are presented. One solution gives a conventional quantum state with q=0 order for all spin values. Another gives a gapped spin liquid state for spin S= 1/2 and a mixed state with both q=0 and √3 × √3 orders for spin S > 1/2 . We emphasize that the mixed state exhibits two sets of peaks in the static spin structure factor. For the case of spin S= 1/2 , the gap value we obtained is consistent with the previous numerical calculations by other means. We also discuss the thermodynamic quantities such as the specific heat and magnetic susceptibility at low temperatures and show that our result is in a good agreement with the Mermin-Wagner theorem.
DRNTU::Science::Physics::Atomic physics::Solid state physics
Physical review B
© 2007 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The paper can be found at: [DOI: http://dx.doi.org/10.1103/PhysRevB.76.174406]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.