Generalized plaquette state in the anisotropic Shastry-Sutherland model
Date of Issue2015-09-25
School of Physical and Mathematical Sciences
We use a generalized Schwinger boson approach to investigate the nature of the intermediate phase (separating the antiferromagnetic and dimer phases) in the Shastry-Sutherland model with exchange anisotropy. Our results confirm the plaquette nature of the intermediate phase and demonstrate that exchange anisotropy (both Ising-like and XY-like) weakens the plaquette order and ultimately suppresses it altogether for sufficiently strong anisotropy. Interestingly, we find that the low-energy excitation spectrum of the plaquette state changes dramatically near the boundary with the dimer phase—the location of the minimum in the (gapped) lowest excitation mode changes from k=(0,0) to four degenerate points.
Physics and Applied Physics
Physical Review B
© 2015 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 published version is available at: [http://dx.doi.org/10.1103/PhysRevB.92.094440]. 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.