Spin Injection into a Luttinger Liquid

Abstract

We study the effect of spin injection into a Luttinger liquid. The spin-injection-detection setup of Johnson and Silsbee is considered: spins injected into the Luttinger liquid induce, across an interface with a ferromagnetic metal, either a spin-dependent current $\left(I_s\right)$ or a spin-dependent boundary voltage $\left(V_s\right)$. We find that the spin-charge separation nature of the Luttinger liquid affects $I_s$ and $V_s$ in a very different fashion. In particular, in the Ohmic regime, $V_s$ depends on the spin transport properties of the Luttinger liquid in essentially the same 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.