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Researchers discovered that trigonal tellurium (Te) and selenium (Se) materials exhibit Weyl nodes. Applying pressure realizes the Weyl semimetal phase, with tunable spin textures observed.

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Area of Science:

  • Condensed Matter Physics
  • Materials Science
  • Quantum Materials

Background:

  • Weyl nodes are exotic topological excitations in quantum materials.
  • Materials lacking inversion symmetry are predicted to host Weyl nodes, but experimental realization remains challenging.

Purpose of the Study:

  • Investigate the existence and properties of Weyl nodes in non-centrosymmetric materials.
  • Explore the potential for realizing the Weyl semimetal phase under external stimuli.

Main Methods:

  • First-principles calculations were employed to analyze the electronic band structure.
  • The study focused on trigonal tellurium (Te) and selenium (Se) under varying pressure conditions.

Main Results:

  • Multiple Weyl nodes were identified near the Fermi level in trigonal Te and Se.
  • A unique radial hedgehog spin texture with a nonzero Pontryagin index was observed in the conduction bands.
  • Applying pressure was found to induce the Weyl semimetal phase.

Conclusions:

  • Trigonal Te and Se are promising candidates for realizing Weyl semimetals without inversion symmetry.
  • Pressure-induced tuning of Weyl nodes and spin textures offers a pathway to control topological properties.