  The spin-resolved non-equilibrium real-time electron transport through a
double-quantum-dot (DQD) Aharonov-Bohm (AB) interferometer with spin-orbit
interaction (SOI) is explored. The SOI and AB interference in the real-time
dynamics of spin transport is expressed by effective magnetic fluxes.
Analytical formulae for the time-dependent currents, for initially unpolarized
spins, are presented. In many cases, there appear spin currents in the
electrodes, for which the spins in each electrode are polarized along
characteristic directions, pre-determined by the SOI parameters and by the
geometry of the system. Special choices of the system parameters yield
steady-state currents in which the spins are fully polarized along these
characteristic directions. The time required to reach this steady state depends
on the couplings of the DQD to the leads. The magnitudes of the currents depend
strongly on the SOI-induced effective fluxes. Without the magnetic flux, the
spin-polarized current cannot be sustained to the steady states, due to the
phase rigidity for this system. For a non-degenerate DQD, transient spin
transport can be produced by the sole effects of SOI. We also show that one can
extract the spin-resolved currents from measurements of the total charge
current.
