English

Deep-lying semi-Dirac fermions in hexagonal close-packed cadmium

Materials Science 2025-11-13 v4 Mesoscale and Nanoscale Physics Statistical Mechanics

Abstract

Semi-Dirac fermions are massless in one direction and massive in the perpendicular directions. Such quasiparticles have been proposed in various contexts in condensed matter. Using first principles calculations, we identify a pair of semi-Dirac bands anti-crossing at 3-3 eV below the Fermi level in the electronic structure of hexagonal close-packed cadmium. The linear out-of-plane dispersion is kept up to the Fermi level. We demonstrate that the dichotomy between the linear and quadratic dispersions is driven by an orientation-sensitive hybridization between the ss and pzp_z orbitals. The upper semi-Dirac band produces a lens-shaped nonellipsoidal Fermi sheet whose cross-section area has a kk-dependence that is in excellent agreement with the experimentally measured period of Sondheimer oscillations.

Keywords

Cite

@article{arxiv.2411.11585,
  title  = {Deep-lying semi-Dirac fermions in hexagonal close-packed cadmium},
  author = {Alaska Subedi and Kamran Behnia},
  journal= {arXiv preprint arXiv:2411.11585},
  year   = {2025}
}
R2 v1 2026-06-28T20:03:33.895Z