  Although the Hubbard model is widely investigated, there are surprisingly few
attempts to study the behavior of such a model in an external magnetic field.
Using the Projector Quantum Monte Carlo technique, we show that the Hubbard
model with an easy axis exhibits metamagnetic behavior if an external field is
turned on. For the case of intermediate correlations strength $U$, we observe a
smooth transition from an antiferromagnetic regime to a paramagnetic phase.
While the staggered magnetization will decrease linearly up to a critical field
$B_c$, uniform magnetization develops only for fields higher than $B_c$.
