Noncollinear spin transport in magnetic multilayers

We study giant magnetoresistance at 4.2 K in magnetic multilayers with noncollinear magnetizations, and various thicknesses of one of the layers. We show that these measurements are extremely sensitive to the transverse spin currents in ferromagnets, and measure the transverse spin-current penetration length into a ferromagnet. The implications of our results for the spin-torque effect are discussed.