Antiferromagnetic Ising model on the swedenborgite lattice
Abstract
Geometrical frustration in spin systems often results in a large number of degenerate ground states. In this work, we study the antiferromagnetic Ising model on the threedimensional swedenborgite lattice, which is a specific stacking of kagome and triangular layers. The model contains two exchange couplings, one within the kagome layer and another in between the kagome and triangular layers. We determine the phase diagram with and without an easyaxis magnetic field, and we calculate the groundstate degeneracy explicitly in terms of the residual entropy. At zero field, we find two different groundstate manifolds separated by a firstorder transition at T =0 and equal exchange couplings. We also determine the T =0 phase diagram in a magnetic field and find a rich phase diagram with both degenerate and nondegenerate phases depending on the field strength and outofplane coupling.
 Publication:

Physical Review B
 Pub Date:
 September 2014
 DOI:
 10.1103/PhysRevB.90.094415
 arXiv:
 arXiv:1406.1382
 Bibcode:
 2014PhRvB..90i4415B
 Keywords:

 75.10.Hk;
 Classical spin models;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 7 pages, 8 figures