Using the zero mode method we compute the conductance of a wire consisting of a magnetic impurity coupled to two Luttinger liquid leads characterized by the Luttinger exponent $\alpha(\leq 1)$. We find for resonance conditions, in which the Fermi energy of the leads is close to a single particle energy of the impurity, the conductance as a function of temperature is $G \sim \frac{ e^2}{ h} (T/T_F)^{ 2(\alpha-2)}$, whereas for off-resonance conditions the conductance is $G \sim \frac{ e^2}{ h} (T/T_F)^{ 2(\alpha-1)}$. By applying a gate voltage and/or a magnetic field, one of the spin components can be in resonance while the other is off-resonance causing a strong asymmetry between the spin-up and spin-down conductances.
Categories: cond-mat.str-el