Electron Transport through a Silicon Atomic Chain

The electron transport properties of a silicon atomic chain sandwiched between Au (100) leads are investigated by using the density functional theory combined with the non-equilibrium Green's function method. The breaking process of Au-Si₄-Au nanoscale junctions is simulated. The conductance and the corresponding cohesion energy as a function of distance d_z are obtained. With the increase of distance, the conductance decreases. When d_z=18.098 ?, there is a minimum value of cohesion energy. The nanoscale structure of junctions is most stable, and the equilibrium conductance is 1.71G₀ (G₀=2e²/h) at this time. The I–V curves of junctions at equilibrium position show linear characteristics.