Related Experiment Video
Updated: May 23, 2026
12:19
Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source
Published on: April 4, 2017
Quantum interference in ring-structured molecular junctions: Effects of electron-phonon coupling and lattice dynamics
Yutong Hao1, Qiuxia Lu1, Yalin Zhang2
1College of Physics and Hebei Advanced Thin Film Laboratory, Hebei Normal University, Shijiazhuang 050024, China.
The Journal of Chemical Physics
|May 22, 2026
Summary
Quantum interference in molecular junctions is influenced by electron-phonon coupling and lattice dynamics. These vibronic effects significantly alter current flow, impacting both constructive and destructive quantum interference pathways.
Area of Science:
- Nanoscience
- Quantum Chemistry
- Condensed Matter Physics
Background:
- Quantum interference (QI) is crucial for electron transport in molecular junctions.
- Electron-phonon (e-ph) coupling and lattice dynamics can significantly influence nanoscale transport phenomena.
- Understanding these effects is key to designing novel electronic devices.
Purpose of the Study:
- To investigate the impact of e-ph coupling and lattice dynamics on QI effects in ring-shaped molecular junctions.
- To elucidate the mechanisms by which vibronic effects modulate constructive quantum interference (CQI) and destructive quantum interference (DQI).
Main Methods:
- Utilized the extended Su-Schrieffer-Heeger model.
- Employed the hierarchical equations of motion approach for simulations.
- Analyzed the role of lattice reconstruction and dynamical lattice evolution.
Main Results:
- In ideal lattices, current shows even-odd dependence on atom number difference, indicating clear CQI and DQI.
- E-ph coupling and lattice reconstruction weaken both CQI and DQI by altering phase accumulation.
- Dynamical lattice evolution strongly suppresses DQI and facilitates excitonic states, enhancing current in both regimes.
Conclusions:
- QI in molecular junctions is determined by geometry, e-ph coupling, and lattice dynamics.
- Vibronic effects play a critical role in modulating quantum interference and electron transport.
- Lattice dynamics can introduce new transport channels via excitonic states, impacting device performance.
Related Concept Videos
02:32The de Broglie Wavelength
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
01:27¹H NMR: Long-Range Coupling
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
01:08NMR Spectroscopy: Spin–Spin Coupling
The spin state of an NMR-active nucleus can have a slight effect on its immediate electronic environment. This effect propagates through the intervening bonds and affects the electronic environments of NMR-active nuclei up to three bonds away; occasionally, even farther. This phenomenon is called spin–spin coupling or J-coupling. Coupling interactions are mutual and result in small changes in the absorption frequencies of both nuclei involved. While nuclei of the same element are involved in...
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
01:27π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...