Effect of metal nanoparticles on polariton dispersion in low dimensional systems

Abstract

The polariton dispersion of a metal nanocomposite-based system is studied for various low dimensional systems. The polariton dispersion of a novel LiNbO3 piezo-electric superlattice is studied for different periods. Al metal nanoparticles are doped in the novel superlattice system and the polariton dispersion is studied for various filling factors. It is found that when percentage of Al metal nanoparticle increases, the frequency of the upper mode increases and also the gap shifts towards longer wave vector region. The polariton dispersions at the brillouin Zone center and at the edge of LiNbO3/LiTaO3 Quantum Well, Quantum Wire and Quantum Dot superlattice systems are studied and compared. Additional modes of propagation are obtained in the dispersion of Al nanoparticle doped low dimensional systems. Some of which reflect the metal behavior of Al particles and some other modes of propagation are found to be degenerate at transverse optical phonon frequencies of LiNbO3/LiTaO3 and at interfacial frequency modes. It is found that the polaritonic gap shift towards lower wave vector region with filling factor. This type of tuning of polaritonic gap can be exploited in the fabrication of novel optical devices especially in the field of communication.