Regensburg 2022 – scientific programme

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O: Fachverband Oberflächenphysik

O 11: Electronic Structure Theory

O 11.5: Talk

Monday, September 5, 2022, 16:00–16:15, H6

Signatures of molecular conformation in the evolution of DFT-based single molecule conductance — •Hector Vazquez — Inst. of Physics, Czech Academy of Sciences

Single molecules placed between two nanoelectrodes represent the ultimate limit in downscaling of electronic components. Electron transport simulations based on DFT-NEGF have enabled the understanding of conducting junctions and the interpretation of experiments [1]. However, these computationally costly calculations are often carried out for a small number of representative junction structures. In contrast, in room temperature experiments, the geometry of the molecule is expected to change significantly.

Here we describe and apply an approximate method to calculate molecular conductance within DFT for thousands of geometries. By combining it with room-temperature molecular dynamics (MD) simulations of the junction [2], we obtain the evolution of conductance for thousands of structure-conductance points. We analyze several geometric parameters and their effect on conductance, including quantum interference. This analysis on large datasets of DFT-based calculations reveals the signatures of molecular structure on junction conductance.

[1] F. Evers, R. Korytar, S. Tewari and J.M. van Ruitenbeek, Rev. Mod. Phys. 92, 35001 (2020)

[2] H. Vazquez, R. Skouta, S. Schneebeli, M. Kamenetska, R.Breslow, L. Venkataraman and M.S. Hybertsen, Nature Nanotechnol. 7, 663 (2012)