Novel time-saving first-principles calculation method for electron-transport properties

TL;DR

This paper introduces a novel, efficient first-principles simulation method that significantly reduces computational time for calculating electron-transport properties in nanostructures using density functional theory.

Contribution

It develops a time-saving simulator incorporating Fourier transform and preconditioning conjugate-gradient algorithms for electron transport calculations.

Findings

Efficient calculation of scattering wave functions and conductance.

Observation of two-atom length oscillations in Ir nanowire conductance.

Agreement with experimental conductance behavior.

Abstract

We present a time-saving simulator within the framework of the density functional theory to calculate the transport properties of electrons through nanostructures suspended between semi-infinite electrodes. By introducing the Fourier transform and preconditioning conjugate-gradient algorithms into the simulator, a highly efficient performance can be achieved in determining scattering wave functions and electron-transport properties of nanostructures suspended between semi-infinite jellium electrodes. To demonstrate the performance of the present algorithms, we study the conductance of metallic nanowires and the origin of the oscillatory behavior in the conductance of an Ir nanowire. It is confirmed that the $s$-$d_{z^2}$ channel of the Ir nanowire exhibits the transmission oscillation with a period of two-atom length, which is also dominant in the experimentally obtained conductance trace.