A time-dependent approach to electronic transmission in model molecular junctions
N Renaud1, M A Ratner, C Joachim
1Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States. n-renaud@northwestern.edu
The Journal of Physical Chemistry. B
|February 18, 2011
Summary
We developed a straightforward quantum mechanics method to calculate electronic transmission. This approach links the time-varying state vector
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Molecular electronics
Background:
- Calculating transmission coefficients is crucial for understanding electron transport in nanoscale devices.
- Traditional methods often rely on time-independent approximations.
Purpose of the Study:
- To present a simple, time-dependent method for computing quantum system transmission coefficients.
- To elucidate the relationship between state vector dynamics and transmission spectra.
- To provide physical insights into resonance and interference phenomena in molecular junctions.
Main Methods:
- Solving the time-dependent Schrodinger equation for a quantum system coupled to electrodes.
- Analyzing the temporal evolution of the state vector.
- Relating oscillation frequency and decay rate of the state vector to the transmission coefficient's line shape.
Main Results:
- Established a direct link between the time evolution of the state vector and the electronic transmission coefficient.
- Demonstrated the influence of oscillation frequency and decay rate on the transmission line shape.
- Validated the method against established techniques for single impurity, two-site, and benzene ring systems.
Conclusions:
- The presented time-dependent method offers a simple and insightful approach to calculating transmission coefficients.
- The method provides new physical understanding of spectral features in molecular junctions.
- This technique is applicable to various quantum systems relevant to molecular electronics.
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