  We study the competition between the p-wave and the p+ip superfluid solutions
in a holographic model with applied magnetic field intensity $H$. We find that
when $H$ is turned on, both the grand potential and the critical temperature of
the p+ip solution are shifted, while the p-wave solution is only slightly
affected. Combining the effect of $H$ and back reaction parameter b, we build
$H-T$ phase diagrams with a slit region of p+ip phase. The zero (or finite)
value of $H$ at the starting point of the slit region is related to second (or
first) order of the p-wave phase transition at zero magnetic intensity, which
should be universal in systems with degenerate critical points (spinodal
points) at zero magnetic field.
