  The Kepler mission has discovered that multiple close-in super-Earth planets
are common around solar-type stars, but their period ratios do not show strong
pile-ups near mean motion resonances (MMRs). One scenario is that super-Earths
form in a gas-rich disk, and they interact gravitationally with the surrounding
gas, inducing their orbital migration. Disk migration theory predicts, however,
that planets would end up at resonant orbits due to their differential
migration speed. Motivated by the discrepancy between observation and theory,
we seek for a mechanism that moves planets out of resonances. We examine the
orbital evolution of planet pairs near the magnetospheric cavity during the gas
disk dispersal phase. Our study determines the conditions under which planets
can escape resonances. We perform two-planet N-body simulations, varying the
planet masses, stellar magnetic field strengths, disk accretion rates and gas
disk depletion timescales. As planets migrate outward with the expanding
magnetospheric cavity, their dynamical configurations can be rearranged.
Migration of planets is substantial (minor) in a massive (light) disk. When the
outer planet is more massive than the inner planet, the period ratio of two
planets increases through outward migration. On the other hand, when the inner
planet is more massive, the final period ratio tends to remain similar to the
initial one. Larger stellar magnetic field strengths result in planets stopping
their migration at longer periods. We highlight \textit{magnetospheric rebound}
as an important ingredient able to reconcile disk migration theory with
observations. Even when planets are trapped into MMR during the early gas-rich
stage, subsequent cavity expansion would induce substantial changes to their
orbits, moving them out of resonance.
