The annealed positions of ferromagnetic bonds doped into a 2D antiferromagnet
Department of Physics, Queen's University - Kingston,
Ontario K7L 3N6, Canada
Accepted: 17 July 1996
We determine where a given concentration of ferromagnetic (FM) bonds doped into a square lattice antiferromagnet must go to minimize the system's total magnetic energy. We find i) an infinite degeneracy of ground-state arrangements of FM bonds that correspond to completely unfrustrated configurations for classical spins, and ii) this degeneracy is lifted when quantum fluctuations are included, and phase-separated ground states, such as periodic arrays of stripes of FM bonds, are found. A discussion of the application of these ideas to doped cuprate high-Tc superconductors with annealed disorder is presented.
PACS: 75.25.+z – Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.) / 71.10.-w – Theories and models of many electron systems
© EDP Sciences, 1996