Infrared surface plasmon and hot carrier properties of topological nodal line semimetal ZrSiS.

Recently, a new plasmon mode, the nodal-line plasmon, was discovered in ZrSiS, which provides promising possibilities for plasmonics or optics. However, there remains a lack of research on the surface plasmon (SP) properties and carrier transport characteristics of ZrSiS. In this paper, we conduct an in-depth study of these properties and compare them with the traditional SP material Au. The interband contribution of the dielectric function of ZrSiS is much greater than the intraband contribution, which is opposite to the properties of traditional SP materials such as Au. In addition, it's found that ZrSiS can generate SP in the infrared range, with the imaginary part of the dispersion relation larger than that of Au and a much shorter propagation length. This implies that ZrSiS has significant potential for generating hot carriers in the infrared range. Notably, the initial energy distribution and hot carrier transport properties indicate that the hot carriers generated by ZrSiS are concentrated in the high-energy region and exhibit good separation. Furthermore, ZrSiS can simultaneously produce long-lived hot electrons and holes with lifetimes comparable to those of Au, which is crucial for the collection and application of hot carriers. Our results not only provide theoretical analysis for understanding the surface plasmonic properties of ZrSiS but also offer important guidance for the collection and application of the carriers in ZrSiS.