Importance of quantum interference in molecular-scale devices

TL;DR

This paper investigates how quantum interference affects electron transport in molecular devices, showing that binding configurations significantly influence transport properties, with implications for molecular electronics design.

Contribution

It introduces a simplified Huckel-like model combined with Newns-Anderson theory to analyze quantum interference effects in molecular-scale devices.

Findings

Transport properties vary greatly with binding configuration.

Quantum interference plays a crucial role in electron transport.

Binding character significantly impacts device performance.

Abstract

Electron transport is theoretically investigated in a molecular device made of anthracene molecule attached to the electrodes by thiol end groups in two different configurations (para and meta, respectively). Molecular system is described by a simple Huckel-like model (with non-orthogonal basis set of atomic orbitals), while the coupling to the electrodes is treated through the use of Newns-Anderson chemisorption theory (constant density of states within energy bandwidth). Transport characteristics (current-voltage and conductance-voltage) are calculated from the transmission function in the standard Landauer formulation. The essential question of quantum interference is discussed in detail. The results have shown a striking variation of transport properties of the device depending on the character of molecular binding to the electrodes.