Destructive quantum interference in heterocyclic alkanes: the search for ultra-short molecular insulators

Abstract

Designing highly insulating sub-nanometer molecules is difficult because tunneling conductance increases exponentially with decreasing molecular length. This challenge is further enhanced by the fact that most molecules cannot achieve full...

Site and length dependent quantum interference and resonance in the electron transport of armchair carbon nanotube molecular junctions

“…Quantum interference (QI) in electron transport of singlemolecule devices is a phenomenon that takes place when two or more pathways of electrons are in phase or out of phase. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] In clear contrast with the double-slit interference of light or electrons for which the interference patterns are observed in real space, quantum interference in electron transport studied here happens in the energy space and is typically accompanied by the increase or decrease of the transmission function in a certain energy range. [19][20][21] In particular, the case of destructive quantum interference (DQI) is characterized by a sharp dip in the transmission function, which leads to a decrease of transmission by several orders of magnitude.…”

Molecular ensemble junctions with inter-molecular quantum interference

“…If, for simplicity, the transmission probability depends on only two MOs, when there is no phase difference between these two paths then QI is constructive and T ( E F ) is high and if the two phases differ by π , then QI is destructive and T ( E F ) is low. Experimental verification of QI in SMJs 11 , 12 has been motivated by prospect harvesting of this phenomena for applications such as highly efficient thermoelectric devices 14 and extremely small perfect insulators 15 , as well as for inducing properties such as highly non-linear I-V characteristics 16 . The main challenge for the realization of these applications is precise control of the parity of the MOs that dominate the transport properties, as well as of their energy position relative to the Fermi energy 8 .…”

Understanding Quantum Interference in Molecular Devices Based on Molecular Conductance Orbitals

“…When electronic devices shrink to the nanoscale, they can present some unique transport properties that are hard to observe at a macroscopic scale. − Quantum interference (QI) is one of these unique phenomena with numerous potential applications such as spin filters, − molecular insulators, − and quantum interference effect transistors. − …”