Terahertz tuning of Dirac plasmons in Bi$_2$Se$_3$ Topological Insulator
Abstract
Light can be strongly confined in sub-wavelength spatial regions through the interaction with plasmons, the collective electronic modes appearing in metals and semiconductors. This confinement, which is particularly important in the terahertz spectral region, amplifies light-matter interaction and provides a powerful mechanism for efficiently generating non-linear optical phenomena. These effects are particularly relevant in Dirac materials like graphene and Topological Insulators, where massless fermions show a naturally non-linear optical behavior in the terahertz range. The strong interaction scenario has been considered so far from the point of view of light. In this paper, we investigate instead the effect of strong interaction on the plasmon itself. In particular, we will show that Dirac plasmons in BiSe Topological Insulator are strongly renormalized when excited by high-intensity terahertz radiation by displaying a huge red-shift down to 60% of its characteristic frequency. This opens the road towards tunable terahertz non-linear optical devices based on Topological Insulators.
Keywords
Cite
@article{arxiv.1910.11233,
title = {Terahertz tuning of Dirac plasmons in Bi$_2$Se$_3$ Topological Insulator},
author = {Paola Di Pietro and Nidhi Adhlakha and Federica Piccirilli and Alessandra Di Gaspare and Jisco Moon and Seongshik Oh and Simone Di Mitri and Simone Spampinati and Andrea Perucchi and Stefano Lupi},
journal= {arXiv preprint arXiv:1910.11233},
year = {2020}
}