Weyl Node and Spin Texture in Trigonal Tellurium and Selenium

Understand

We study Weyl nodes in materials with broken inversion symmetry.

• We find based on first-principles calculations that trigonal Te and Se have multiple Weyl nodes near the Fermi level.
• The conduction bands have a spin splitting similar to the Rashba splitting around the H points, but unlike the Rashba splitting the spin directions are radial, forming a hedgehog spin texture around the H points, with a nonzero Pontryagin index for each spin-split conduction band.
• The Weyl semimetal phase, which has never been observed in real materials without inversion symmetry, is realized under pressure.