Abstract
We study a generalized Shastry-Sutherland model for the material . Along a line in the parameter space, we show rigorously that the model has a first-order phase transition between dimerized and Néel-ordered ground states. Furthermore, when a magnetic field is applied in the dimerized phase, magnetization plateaus develop at commensurate values of the magnetization. We also discuss various aspects of the phase diagram and properties of this model away from this exactly soluble line, which include gap-closing continuous transitions between dimerized and magnetically ordered phases.
- Received 7 October 1999
DOI:https://doi.org/10.1103/PhysRevLett.84.1808
©2000 American Physical Society