3D Dirac Plasmons in the Type-II Dirac Semimetal PtTe_{2}

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Transition-metal dichalcogenides with type-II Dirac fermions are promising for nanoelectronics.
• The excitation spectrum of these materials remains largely unexplored.

Purpose of the Study:

• To identify and characterize the collective excitations of type-II Dirac fermions in platinum telluride (PtTe₂) single crystals.
• To explore the potential of PtTe₂ for optoelectronic applications.

Main Methods:

• High-resolution electron energy loss spectroscopy (HREELS).
• Density functional theory (DFT) calculations.

Main Results:

• Identification of 3D Dirac plasmons in PtTe₂ single crystals.
• Observed plasmon energy of approximately 0.5 eV at the long-wavelength limit.
• Discovery of additional excitations at approximately 1 eV and 1.4 eV due to interband transitions.

Conclusions:

• PtTe₂ exhibits 3D Dirac plasmons, making it suitable for near-infrared optoelectronic applications.
• The identified excitations are crucial for the practical application of type-II Dirac semimetals in optoelectronics.