Dresden 2014 – scientific programme

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O: Fachverband Oberflächenphysik

O 101: Molecular Films: Electronics, Photovoltaics and Structure

O 101.5: Talk

Friday, April 4, 2014, 11:30–11:45, WIL A317

Analysis of constructive quantum interference effects in single molecule circuits with parallel backbones — •Hector Vazquez¹, Rachid Skouta², Severin Schneebeli², Maria Kamenetska³, Ronald Breslow², Latha Venkataraman³, and Mark S. Hybertsen⁴ — ¹Institute of Physics, AS CR, Prague, Czech Republic — ²Dept. of Chemistry, Columbia University, USA — ³Dept. of Appl. Phys. and Appl. Mathem., Columbia University, USA — ⁴Center for Functional Nanomaterials, Brookhaven National Laboratory, USA

Quantum interference effects play an important role in single molecule transport. Several examples of destructive quantum interference in molecular transport have been measured [1,2]. Recently, we studied the conductance superposition law in molecular circuits and demonstrated constructive quantum interference effects [3]. We showed that molecules with two branches bound in parallel to the electrodes can exhibit more than twice the conductance of the single backbone counterparts.

Here we extend our analysis to quantify the effect of junction geometry on the conductance of single and double backbone molecules. In this talk I will present results from DFT-NEGF based methods, and discuss the role of junction structure (eg. molecular rotations) in observing clear signatures of interference effects.

[1] J. Am. Chem. Soc. 133, 9556 (2011). [2] Nat. Nanotechnol. 7, 305 (2012). [3] Nat. Nanotechnol. 7, 663 (2012).