Magneto-scanning near-field optical microscopy in Dirac materials

Recently, Dirac materials have been drawing much attention as their gapless linear dispersion around band crossings (Dirac points) host various novel phenomena such as quantum magnetoresistance, chiral magnetic effect, anomalous thermoelectric effect, and so on. Among them, it has shown that surface plasmon polaritons (SPPs) in Dirac materials owing to their high mobility is less Ohmic loss compared to conventional noble metals like Au, Ag, etc., paving the way for controlling phonons beyond diffraction limit. In PtTe2, one of the Dirac semimetals, SPPs have been reported in several experimental studies using scanning near-field optical microscopy (SNOM)^1,2. In this talk, we’ll show the results of our newly developed magneto-SNOM (m-SNOM) to investigate field dependence of plasmonic patterns and the tunability of the plasmon wavelength via magnetic field will be discussed.

Reference

1. 1. Lei Fu, et al., Highly Organized Epitaxy of Dirac Semimetallic PtTe2 Crystals with Extrahigh Conductivity and Visible Surface Plasmons at Edges, ACS Nano 2018 12 (9), 9405-9411 (2018).
   
   2. Xin Hu, et al., Infrared Nanoimaging of Surface Plasmons in Type-II Dirac Semimetal PtTe2 Nanoribbons, ACS Nano 2020, 14, 5, 6276–6284 (2020).