Tunnelling of Polarized Electrons in Magnetic Wires

We investigate the tunnelling between an electronic gas with two different velocities $V_{\uparrow }\mathrm{\ne }{V}_{\downarrow }$ and a regular metal. We find that at the interface between the two systems that the tunnelling conductance for spin up and spin down are different. As a result a partly polarized gas (``magnetic wire’‘) is obtained. This result is caused by the e-e interaction, $g_2’’ - g_1’’ \neq 0$,whichinthepresenceof$V_\uparrow \neq V_\downarrow$ gives rise to two different tunnelling exponents.