First-principles study of electron transport in Si atom wires under finite bias voltage

We have theoretically analyzed electron transport in wires consisting of one to three Si atoms at a finite bias voltage using a first-principles method. The electronic states and transport properties are calculated in the framework of density functional theory using the Lippmann–Schwinger equation in the Laue representation. We analyzed the transport properties of Si wires between metallic electrodes and elucidated the effects of metallic contacts on a Si atom wire, the characteristics of conduction channels, and their dependence on the bias voltage. The conduction channels are analyzed using eigenchannel decompositions, and it is found that the three channels contributing to the transport are almost open in the bias window under a finite bias voltage.