How to Characterize Plasmonic Excitations with Quantum Mechanical Approach?
Paper ID : 1438-ICNS
Authors:
Zahra Jamshidi *
Chemistry Department, Sharif University of Technology
Abstract:
The quantum plasmonic features of small gold and silver nanostructures with different shapes and sizes are investigated. We obtain the considerable effect of scalar relativistic effects as well as spināˆ’orbit on the intensity and energy of plasmonic excitations. The efficiency of first principle approaches that are based on time-dependent density functional theory and the ability to treat quantum mechanical effects in large nanostructures are studied.
Excited state calculations based on first principle time-dependent density functional theory (TD-DFT) are computationally quite demanding, and their cost increases with the size and number of excitations. Therefore, the TD-DFT algorithm is very efficient for small system or low energy transitions. Moreover, the efficient approaches have been proposed and implemented; TD-DFT+TB base on tight-binding approximation and POLTD-DFT base on the imaginary part of the polarizability. In this work, these new low-cost formalisms are applied to identify the plasmon excitations for pure and alloy Ag and Au with various size, shape and composition and compared the results with TD-DFT.
Keywords:
Plasmonic properties, Gold and Silver Alloy, Time-dependent DFT, Tight-binding
Status : Abstract Accepted (Oral Presentation)