  By performing 2.5-dimensional general relativistic radiation
magnetohydrodynamic simulations, we demonstrate supercritical accretion onto a
non-rotating, magnetized neutron star, where the magnetic field strength of
dipole fields is $10^{10}$ G on the star surface. We found the supercritical
accretion flow consists of two parts; the accretion columns and the truncated
accretion disk. The supercritical accretion disk, which appears far from the
neutron star, is truncated at around $\sim 3R_*$ ($R_*=10^6$ cm is the neutron
star radius), where the magnetic pressure via the dipole magnetic fields
balances with the radiation pressure of the disks. The angular momentum of the
disk around the truncation radius is effectively transported inward through
magnetic torque by dipole fields, inducing the spin up of a neutron star. The
evaluated spin up rate, $\sim -10^{-11}$ s s$^{-1}$, is consistent with the
recent observations of the ultra luminous X-ray pulsars. Within the truncation
radius, the gas falls onto neutron star along dipole fields, which results in a
formation of accretion columns onto north and south hemispheres. The net
accretion rate and the luminosity of the column are $\sim 66L_{\rm Edd}/c^2$
and $\lesssim 10L_{\rm Edd}$, where $L_{\rm Edd}$ is the Eddington luminosity
and c is the light speed. Our simulations support a hypothesis whereby the
ultra luminous X-ray pulsars are powered by the supercritical accretion onto
the magnetized neutron stars.
