Tunable three-way valley Hall energy-splitter: venturing beyond graphene-like structures
Abstract
Strategically combining four structured domains creates the first ever three-way topological energy-splitter; remarkably, this is only possible using a square, or rectangular, lattice, and not the graphene-like structures more commonly used in valleytronics. To achieve this effect, the two mirror symmetries, present within all fully-symmetric square structures, are broken; this leads to two nondistinct interfaces upon which valley-Hall states reside. These interfaces are related to each other via the time-reversal operator and it is this subtlety that allows us to ignite the third outgoing lead. The geometrical construction of our structured medium allows for the three-way splitter to be adiabatically converted into a wave steerer around sharp bends. Due to the tunability of the energies directionality by geometry, our results have far-reaching implications for applications such as beam-splitters, switches and filters across wave physics.
Cite
@article{arxiv.1901.01937,
title = {Tunable three-way valley Hall energy-splitter: venturing beyond graphene-like structures},
author = {Mehul P. Makwana and Gregory J. Chaplain},
journal= {arXiv preprint arXiv:1901.01937},
year = {2021}
}