Infrared Nanoimaging of Surface Plasmons in Type-II Dirac Semimetal PtTe2 Nanoribbons

Xin Hu, Kin Ping Wong, Longhui Zeng, Xuyun Guo, Tong Liu, Lei Zhang, Qin Chen, Xuefeng Zhang, Ye Zhu, Kin Hung Fung, Shu Ping Lau

Research output: Journal article publicationJournal articleAcademic researchpeer-review

20 Citations (Scopus)


Topological Dirac semimetals made of two-dimensional transition-metal dichalcogenides (TMDCs) have attracted enormous interest for use in electronic and optoelectronic devices because of their electron transport properties. As van der Waals materials with a strong interlayer interaction, these semimetals are expected to support layer-dependent plasmonic polaritons yet to be revealed experimentally. Here, we demonstrate the apparent retardation and attenuation of mid-infrared (MIR) plasmonic waves in type-II Dirac semimetal platinum tellurium (PtTe 2) nanoribbons and nanoflakes by near-field nanoimaging. The attenuated dispersion relations for the plasmonic modes in the PtTe 2 nanoribbons (15-25 nm thick) extracted from the near-field standing-wave patterns are applied for the fitting of PtTe 2 permittivity in the MIR regime, indicating that both free carriers and Dirac fermions are involved in MIR light-matter interaction in PtTe 2. The annihilation of plasmonic modes in the ultrathin (<10 nm) PtTe 2 is observed and analyzed, which manifests no near-field resonant pattern due to the intrinsic layer-dependent optoelectronic properties of PtTe 2. These results could pave a potential wave for MIR photodetection and modulation with TMDC semimetals.

Original languageEnglish
Pages (from-to)6276-6284
Number of pages9
JournalACS Nano
Issue number5
Publication statusPublished - 26 May 2020


  • Dirac semimetals
  • platinum tellurium nanoribbons
  • s-SNOM
  • surface plasmons
  • transition-metal dichalcogenides

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)


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