Abstract
Bound states made from two triplet excitations on the Shastry-Sutherland lattice are investigated. Based on the perturbative unitary transformation by flow equations quantitative properties like dispersions and qualitative properties like symmetries are determined. The high order results [up to ] permit one to fix the parameters of precisely: , , . At the border of the magnetic Brillouin zone a general double degeneracy is derived. An unexpected instability in the triplet channel at indicates a transition towards another phase. The possible nature of this phase is discussed.
- Received 19 May 2000
DOI:https://doi.org/10.1103/PhysRevLett.85.3958
©2000 American Physical Society