Quantum interference and spin filtering effects in photo-responsive single molecule devices

Abstract

The development of stimuli responsive systems that can switch between two distinct spin states under the application of an external stimuli has always remained an illusory challenge. Here, we report...

Quantum Interference Controlled Spin-Polarized Electron Transmission in Graphene Nanoribbons

“…Exploiting quantum interference (QI) effects is another effective method for controlling electron transport. − This phenomenon has been extensively discussed in molecular junctions consisting of benzene and other π-conjugated systems, where the relative positions of anchoring groups (para or meta) affect the molecular conductance. − O’Driscoll et al. demonstrated experimentally and computationally that the presence of heteroatom in conduction pathway increase the effect of changing the anchoring group by utilizing the destructive quantum interference (DQI) in molecular junctions .…”

Anti-ohmic Nanoconductors: Myth, Reality and Promise

“…However, as compared to p-acenes, m-acenes shows sharp dips near Fermi energy owing to DQI effects associated with the phase difference between electron waves traversing across the molecule. 43,44 Noteworthy, since the electronic structure calculations in OSS state for n = 1 to 6 acenes converges to CSS ground state with ∆EOSS−CSS = 0 (Figure 1a), so does the transport calculations with identical transmission spectra and frontier orbital energies for closed shell and open shell calculations.…”

“…53 The Au-Au distance is set to 2.88 Å and Au-S distance is fixed to 2.40 Å, which is similar to our previous reported works. 40,43 Electron Transport calculations. The electron transport calculations are performed using Non-Equilibrium Green's Function combined with DFT (NEGF-DFT) as implemented in Artaios 54 using B3LYP exchange correlation functional in combination with LANL2DZ basis set.…”

Anti-ohmic Nanoconductors: Myth, Reality and Promise

“…The Au-Au distance is set to 2.88 Å and Au-S distance is fixed to 2.40 Å, which is similar to our previous reported works. 51,52 The electron transport calculations are performed using Non-Equilibrium Green's Func-tion combined with DFT (NEGF-DFT) as implemented in Artaios 53 using B3LYP exchange correlation functional in combination with LANL2DZ basis set. Accordingly, the model used in transmission calculations is divided into three regions: central (C) scattering region formed by the di-thiolated molecule, and the left (L) and right (R) electrode consisting of Au 9 clusters.…”

“…However, as compared to p-acenes, m-acenes shows sharp dips near Fermi energy owing to DQI effects associated with the phase difference between electron waves traversing across the molecule. 52,71,72 Noteworthy, since the electronic structure calculations in OSS state for n = 1 to 6 acenes converges to CSS ground state with ∆E OSS−CSS = 0 (Figure 1a), so does the transport calculations with identical transmission spectra and frontier orbital energies with CSS ground state while for higher acenes with OSS ground state, the use of CSS solution is merely a computational artifact which leads to artificially enhanced transmission. Thus, the use of unrestricted solution for molecules bearing diradical character is mandatory for accurate estimation of conductance.…”