Nonlinear plasmonics of three-dimensional Dirac semimetals

Kelvin J A Ooi,Dawn T H Tan,C K Ong,Y S Ang,Q Zhai,L K Ang

doi:10.1063/1.5042450

Abstract

The three-dimensional Dirac semimetal (3D DSM) is a new class of material with a slew of electronic and optical properties in common with graphene, while structurally having a bulk form like real metals. In particular, the Dirac band structure of 3D DSM conferred very high optical nonlinearities much like the case for graphene. Consequently, we found that 3D DSM has respectable nonlinear plasmonic performance in comparison with graphene, while retaining the structural benefits of bulk metals, having reduced passive plasmonic losses, and is much easier to handle in fabrication facilities. 3D DSM is expected to play a strong role in providing strong optical nonlinearities for all-optical switching and at the same time offering a superior platform for nanophotonic device integration.

Highlights

The road to all-optical computing banks on the advancement of nonlinear optical materials
The all-optical transistor demands a good medium for light-on-light control, which is availed through materials with high Kerr coefficients, low optical losses, and a small form factor
There is without doubt that in terms of the optical nonlinear performance, graphene plasmonics still reigns supreme over most nonlinear materials discovered to date

Summary

Introduction

The road to all-optical computing banks on the advancement of nonlinear optical materials. In 2014, the existence of the topological Dirac nodal point in bulk materials has been experimentally confirmed in sodium bismuth (Na3Bi) by Liu et al.31 and in cadmium arsenide (Cd2As3) by Borisenko et al.32 and Neupane et al.33 In terms of photonic applications, recent progress has seen Cd2As3 being implemented as a saturable absorber for ultrafast midinfrared lasers, traversing the same beginnings of its predecessor graphene.34,35 As the charge carriers are described by Dirac physics in both 2D graphene and 3D DSM, it is widely expected that 3D DSM would share similar Dirac-type optical properties with graphene, such as the tunability of its optical conductivity, strong light confinement, and high nonlinear optical coefficients.

Results

Conclusion