2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27682By deriving a generalized Harper's equation, we investigate the effects of temperature $T$ and hole doping $\d$ on antiferromagnetically correlated electrons under the influence of an applied magnetic field. We obtain a phase diagram in a $T$-$\d$ plane for staggered magnetization under the external field. We find that away from half filling the maximum values of staggered magnetization occur with rapid convergence to a finite temperature constant near half filling. We discover the reentrant behavior of the staggered magnetization in the presence of the magnetic field.4 pages RevTex, uses epsf,twocolumn, 7 postscript figures, submitted to Phys. Rev. LettCondensed Mattertext