Quantum transport through Ga₂As₂ cluster

¹ College of Physics and Electronic Engineering, Yibin University, Yibin 644000, P.R. China
² College of Physical Science and Technology, Sichuan University, Chengdu 610064, P.R. China
³ Computational Physics Key Laboratory of Sichuan Province of Yibin university, Yibin 644000, P.R. China

^a e-mail: futiliu@163.com

Received: 23 January 2014
Revised: 1 March 2014
Accepted: 11 April 2014
Published online: 10 June 2014

Abstract

The electronic transport properties of Ga₂As₂ cluster, which is sandwiched between two semiinfinite Au (1 0 0)-3 × 3 pyramical-shaped electrodes with the Ga-Ga axis of the cluster parallel to the transport direction and the As-As axis of the cluster parallel to the transport direction, respectively, is investigated with a combination of density functional theory and the non-equilibrium Green’s function method. We have simulated the nanoscale junctions breaking process and found that the conductance of cluster decreases then increases when the contact is pulled apart in two configurations. We analyzed the difference of conductance from transmission spectra and projected density of states, and calculated the I-V characteristics of devices in this two configurations when d_z = 2.0 Å. The I-V curves display a linear characteristics in the voltage range of 0 ∼ 2.2 V. The negative differential resistance appears within a small range of voltage in the junctions with As-As axis of the cluster parallel to the transport direction when bias is larger than 2.2 V.