  We observe a stable intermediate resistance switching state in the current
perpendicular to plane geometry for all Co/Cu/Co double layer nanopillar
junctions grown by molecular beam epitaxy. This novel state has a resistance
between the resistances of the parallel and antiparallel alignment of both
Co-layer magnetizations. The state, which originates from an additional
in-plane magnetic easy axis, can be reached by spin transfer torque switching
or by an external magnetic field. In addition to spin torque-induced coherent
small-angle spin wave modes we observe a broad microwave emission spectrum. The
latter is attributed to incoherent magnetic excitations that lead to a
switching between the intermediate state and the parallel or antiparallel
alignment of both ferromagnetic layers. We conclude that the additional
magnetic easy axis suppresses a stable trajectory of coherent large-angle
precession, which is not observed in our samples.
