Compensation Point Phenomena in a Transverse Ising Antiferromagnet: Unconventional Effects of an Applied Magnetic Field

The thermal variations of magnetizations in a transverse Ising antiferromagnet consisting of two magnetic (A and B) layers are examined by the use of the effective-field theory with correlations, applying a magnetic field p. Particular attentions are paid to the systems with a compensation point in the zero applied field (p = 0.0), when crystallographically equivalent conditions between the A and B layers are broken. We find some characteristic phenomena, such as the possibility of more than one compensation point induced by a finite applied magnetic field and the thermally induced first-order transition.