Photoinduced interfacial chiral modes in threefold topological semimetal*

We investigate the chiral electronic modes at the interface between two regions of a threefold
topological semimetal, which is illuminated by left and right handed elliptically polarized waves.
The radiation effects on the band structure of semimetal is analyzed by using Floquet theory. Two
distinct solutions of the interface modes are found with the chirality depending on the phase of
the irradiation. We also consider the anomalous Hall response which is attributed to the interband
contribution between dispersionless flat band and conic bands.