摘要
The low conductance of nickel atomic junctions in tile hydrogen environment is studied using the nonequilibrium Green＇s function theory combined with first-principles calculations. The Ni junction bridged by a H2 molecule has a conductance of approximately 0.7 Go. This conductance is contributed by the anti-bonding state of the H2 molecule, which forms a bonding state with tile 3d orbitals of the nearby Ni atoms. In contrast, the Ni junction bridged by the two single H atoms has a conductance of approximately 1 Go, which is weakly spin-polarized. The spin-up channels were found to contribute mostly to the conductance at a small junction gap, while the spin-down channels play a dominant role at a larger junction gap.
The low conductance of nickel atomic junctions in tile hydrogen environment is studied using the nonequilibrium Green＇s function theory combined with first-principles calculations. The Ni junction bridged by a H2 molecule has a conductance of approximately 0.7 Go. This conductance is contributed by the anti-bonding state of the H2 molecule, which forms a bonding state with tile 3d orbitals of the nearby Ni atoms. In contrast, the Ni junction bridged by the two single H atoms has a conductance of approximately 1 Go, which is weakly spin-polarized. The spin-up channels were found to contribute mostly to the conductance at a small junction gap, while the spin-down channels play a dominant role at a larger junction gap.
基金
This work was financially supported by the National Natural Science Foundation of China （NSFC） under Grant Nos. 11674231 and 11504395.
