Synopsis: 3D Dirac Plasmons

Experiments provide evidence of 3D Dirac plasmons in a bulk material—quasiparticles that could enable novel electronic nanodevices.
Synopsis figure
A. Politano/Italian Institute of Technology–Graphene Labs

Plasmons—quantized collective oscillations of electrons found in conventional metals and semiconductors—are attracting interest for applications in sensing, fast electronics, and solar cell technology. Plasmons can also exist in exotic solids known as Dirac materials. Dirac plasmons present many advantages over conventional ones, such as a higher propagation velocity and frequency tunability. Dirac plasmons have so far been observed in 2D materials like graphene. However, 2D plasmons are extremely sensitive to the presence of defects and contaminants on the material’s surface. Now, Antonio Politano, from the Italian Institute of Technology–Graphene Labs in Genoa, and colleagues have provided direct evidence of 3D Dirac plasmons in the bulk of platinum ditelluride (PtTe2).

Recent research showed that PtTe2 is a 3D type-II Dirac semimetal, a quantum solid sometimes viewed as a “3D graphene.” The team characterized the material’s electronic excitation with high-resolution electron-energy-loss spectroscopy and interpreted the data by comparing them with density-functional-theory predictions. The analysis revealed electronic quasiparticles collectively moving in energy bands with the anisotropic tilted cones characteristic of a type-II Dirac semimetal. These features allowed the team to conclude that these quasiparticles are 3D Dirac plasmons.

The robustness of these 3D plasmons could be harnessed to realize plasmon-based nanodevices like photodetectors. The researchers envision that, since the material is easily cleaved, such devices could be built using thin PtTe2 layers. What’s more, the data showed that the plasmons could be excited with an energy of about 0.5 eV, corresponding to a wavelength of about 2.4 𝜇m. This property could enable optoelectronic applications in which plasmons are controlled with near-infrared laser light.

This research is published in Physical Review Letters.

–Maria Longobardi

Maria Longobardi is a freelance writer based in Geneva, Switzerland.


More Features »


More Announcements »

Subject Areas

PlasmonicsCondensed Matter Physics

Previous Synopsis

Next Synopsis

Related Articles

Viewpoint: Graphene Is Thin, but Not Infinitely So
Condensed Matter Physics

Viewpoint: Graphene Is Thin, but Not Infinitely So

Atomically thin graphene is considered a prototypical 2D material, but high-pressure experiments now reveal the 3D nature of its mechanical properties. Read More »

Synopsis: Tinkering with Superconductivity in a Quasicrystal

Synopsis: Tinkering with Superconductivity in a Quasicrystal

Quasicrystals might host an exotic superconducting phase when subjected to a magnetic field, according to a theoretical study. Read More »

Viewpoint: Questioning a Universal Law for Electron Attenuation
Materials Science

Viewpoint: Questioning a Universal Law for Electron Attenuation

A law describing electron attenuation in solids has long helped researchers determine the size of nanoscale objects, but experiments show that it is less general than previously thought. Read More »

More Articles