Characteristic Length Scale for Spin Polarized Tunneling in Langmuir-Blodgett Molecular Magnetic Tunnel Junction

Using ab initio methods, we have calculated the characteristic inverse length scale for spin polarized tunneling in Langmuir-Blodgett (LB) films contacted by Fe electrodes. As a function of energy, the scale is found to vary significantly around its mean value, and the variation is much more drastic in parallel configuration than that of anti-parallel configuration. This unusual behavior can be understood from the point of view of interface resonance, which shows very sharp features in the k-space resolved transmission probability.