Molecular junction by tunneling in 1D and quasi-1D systems

• Published in: Journal of physics. Condensed matter Vol. 31; no. 44; p. 445501
• Main Authors: Moura-Moreira, Mayra, Felipe Silva Ferreira, Denner, Liu, Shuanglong, Fry, James N, Del Nero, Jordan, Cheng, Hai-Ping
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 06.11.2019
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; electron transport; molecular junction; tunneling; Molecular Junction; Tunneling; Electron Transport
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/ab315a

We have investigated electron tunneling through two one-dimensional (1D) molecular junctions based on first-principles simulations using the density functional theory combined with the non-equilibrium Green's functions methodology. The first junction, composed of left and right carbyne wire electrodes with a sodium atom in between, is atomically thin. The second one is quasi-one-dimensional (quasi-1D) and consists of two single-wall carbon nanotube electrodes, closed on the tips and again a sodium atom in the scattering region. Although the bridging atom bonds weakly to the electrodes in both systems, it strongly affects the electronic transport properties, such as electron transmission, current-voltage relation, differential conductance, density of states and eigenchannels. This is demonstrated by comparing with the results obtained from the corresponding systems for both the 1D and the quasi-1D junctions in the absence of the central sodium atom. The revealed transport properties are sensitive to the molecular geometry. This helps future molecular electronic device design.