Quantum Interference Controlled Molecular Electronics

TL;DR

This paper explores how quantum interference effects can be used to control current in molecular electronics, highlighting the importance of molecular size and contact interactions for effective device design.

Contribution

It demonstrates the dependence of quantum interference effects on molecular size and contact interactions, proposing large molecular rings as potential QIE transistors.

Findings

QIE depends on pi-sigma interactions in molecules.

Small rings like benzene show no QIE due to hybridization.

Large rings like [18]annulene preserve QIE, enabling transistor applications.

Abstract

Quantum interference in coherent transport through single molecular rings may provide a mechanism to control current in molecular electronics. We investigate its applicability by using a single-particle Green function method combined with ab initio electronic structure calculations. We find that the quantum interference effect (QIE) depends strongly on the interaction between molecular pi states and contact sigma states. It is absent in small molecular rings with Au leads, such as benzene, due to strong pi-sigma hybridization, while it is preserved in large rings, such as [18]annulene, which then could be used to realize QIE transistors.