Half-Metallic Sandwich Molecular Wires with Negative Differential Resistance and Sign-Reversible High Spin-filter Efficiency

Using density functional theory and non-equilibrium Green's function method, we construct organometallic nanowires that consist of Fe or V atoms sandwiched between composite molecules (Cp$^{\ast }$FeCp$^{\ast }$, where Cp$^{\ast }$ is C$_{5}$(CH$_{3})_{5})$. For the first time, we demonstrate that half-metallicity, negative differential resistance, and sign-reversible high spin-filter capability can coexist remarkably in one organometallic nanowire (FeCp$^{\ast }$ wire). This renders FeCp$^{\ast }$ wire promising in electronics and spintronics.