  We theoretically investigate the unusual features of the magnetotransport in
a monolayer phosphorene ferromagnetic/normal/ferromagnetic (F/N/F) hybrid
structure. We find that the charge conductance can feature a minimum at
parallel (P) configuration and a maximum near the antiparallel (AP)
configuration of magnetization in the F/N/F structure with $n$-doped F and
$p$-doped N regions and also a finite conductance in the AP configuration with
the N region of $n$-type doping. In particular, the proposed structure exhibits
giant magnetoresistance, which can be tuned to unity. This perfect switching is
found to show strong robustness with respect to increasing the contact length
and tuning the chemical potential of the N region with a gate voltage. We also
explore the oscillatory behavior of the charge conductance or magnetoresistance
in terms of the size of the N region. We further demonstrate the penetration of
the spin-transfer torque into the right F region and show that, unlike graphene
structure, the spin-transfer torque is very sensitive to the chemical potential
of the N region as well as the exchange field of the F region.
