  Electronic transport through a single-molecule magnet Mn$_{12}$ in a
two-terminal set up is calculated using the non-equilibrium Green's function
method in conjunction with density-functional theory. A single-molecule magnet
Mn$_{12}$ is bridged between Au(111) electrodes via thiol group and alkane
chains such that its magnetic easy axis is normal to the transport direction. A
computed spin-polarized transmission coefficient in zero-bias reveals that
resonant tunneling near the Fermi level occurs through some molecular orbitals
of majority spin only. Thus, for low bias voltages, a spin-filtering effect
such as only one spin component contributing to the conductance, is expected.
This effect would persist even with inclusion of additional electron
correlations.
