Effects of magnetic field on the two-dimensional systems of antiferromagnetically correlated electrons based on the Hubbard model Hamiltonian with easy axis: Aharonov-Bohm and Zeeman effects

In the present study we study the two-dimensional systems of antiferromagnets with easy axis and the variation of staggered magnetization with the increase of magnetic fields. The Aharonov-Bohm and the Zeeman effects on the staggered magnetizations are examined. The reentrant behavior of paramagnetic phase is shown to occur even at extremely high applied magnetic fields when only the Aharonov-Bohm effect is taken into account. An inhomogeneous phase (i.e., the inhomogeneous distribution with antiferromagnetic clusters) is also shown to exhibit the reentrant behavior. On the other hand, when the Zeeman effect is introduced, the reentrant behavior occurs only at low fields below a critical magnetic field corresponding to a critical Zeeman energy close to the hopping energy in the order of magnitude.