Orientation dependence of surface critical phenomena in antiferromagnets: exact results in two dimensions
For an Ising antiferromagnet, we analyze exact expressions for the one- and two-point correlation functions for spins on the edge of a square lattice with a magnetic field applied to the surface sites. Two different edge orientations, with respect to the crystal axes, are treated. At bulk criticality, we confirm that the surface universality class depends on the edge orientation and show the importance of having the bulk phase in a pure state. For the two-point function, we find a singularity in the correlation length due to depinning effects which we argue is also present in higher dimensions.
Abraham
DB
Center For Nonlinear Studies, MS-B258, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 and Theoretical Physics, Department of Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
Upton
PJ