Plasmonic detection of the parity anomaly in a two-dimensional Chern insulator

In this work, we present an analytical study on the surface plasmon polaritons in a two dimensional parity anomaly Chern insulator. The connections between the topology in the bulk implied by the BHZ model and the dispersion relations of the surface plasmons have been revealed. Anisotropy has been considered during the calculations of the dispersion relations which allows different permittivities perpendicular to the conductive plane. Two surface plasmon modes each contains two branches of dispersion relations have been found. The topologically non-trivial case gives quite different Hall conductivities compared with the trivial one, which leads to significant modifications of the dispersion curves or even the absence of particular branch of the surface plasmons. Our investigations pave a possible way for the detection of the parity anomaly in a two-dimensional Chern insulator via plasmonic responses.