SPIN INJECTION INTO A LUTTINGER LIQUID

We study the effect of spin injection into a Luttinger liquid. The spi n-injection-detection setup of Johnson and Silsbee is considered: spin s injected into the Luttinger liquid induce, across an interface with a ferromagnetic metal, either a spin-dependent current (I-s) or a spin -dependent boundary voltage (V-s). We find that the spin-charge separa tion nature of the Luttinger liquid affects I-s and V-s in a very diff erent fashion. In particular, in the Ohmic regime, V-s depends on the spin transport properties of the Luttinger liquid in essentially the s ame way as it would in the case of a Fermi liquid. The implications of our results for the spin-injection-detection experiments in the high- T-c cuprates are discussed. [S0031-9007(98)07319-0].