  We analyze the effect of Rashba spin-orbit coupling and of a local tunnel
barrier on the persistent spin and charge currents in a one-dimensional
conducting Aharonov-Bohm (AB) ring symmetrically coupled to two leads. First,
as an important consequence of the spin-splitting, it is found that a
persistent spin current can be induced which is not simply proportional to the
charge current. Second, a magnification effect of the persistent spin current
is shown when one tunes the Fermi energy near the Fano-type antiresonances of
the total transmission coefficient governed by the tunnel barrier strength. As
an unambiguous signature of spin-orbit coupling we also show the possibility to
produce a persistent pure spin current at the interference zeros of the
transmittance. This widens the possibilities of employing mesoscopic conducting
rings in phase-coherent spintronics applications.
