Eightfold Fermionic Excitation in a Charge Density Wave Compound

Abstract

Unconventional quasiparticle excitations in condensed matter systems have become one of the most important research frontiers. Beyond two- and fourfold degenerate Weyl and Dirac fermions, three-, six- and eightfold symmetry protected degeneracies have been predicted however remain challenging to realize in solid state materials. Here, charge density wave compound TaTe4 is proposed to hold eightfold fermionic excitation and Dirac point in energy bands. High quality TaTe4 single crystals are prepared, where the charge density wave is revealed by directly imaging the atomic structure and a pseudogap of about 45 meV on the surface. Shubnikov de-Haas oscillations of TaTe4 are consistent with band structure calculation. Scanning tunneling microscopy reveals atomic step edge states on the surface of TaTe4. This work uncovers that charge density wave is able to induce new topological phases and sheds new light on the novel excitations in condensed matter materials.

arXiv commentAccepted by PRB: https://journals.aps.org/prb/accepted/7907cK4eW0b1ee0b93fd67c1b42942bbb08eafc3c

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Cited by in corpus (16)

• Multiple-Fold Fermions and Topological Fermi Arcs Induced Catalytic Enhancement in Nanoporous Electride C12A7
• Axionic Band Topology in Inversion-Symmetric Weyl-Charge-Density Waves
• Coexistience of phononic six-fold, four-fold and three-fold excitations in ternary antimonide Zr3Ni3Sb4
• Chirality locking charge density waves in a chiral crystal
• Realization of Practical Eightfold Fermions and Fourfold van Hove Singularity in TaCo${}_2$Te${}_2$
• Manipulating Hubbard-type Coulomb blockade effect of metallic wires embedded in an insulator
• Direct observation of discommensurate charge density wave modulation in the quasi-1D Weyl semimetal candidate NbTe${}_4$
• Discovery of a Topological Charge Density Wave
• Orbital-selective charge-density wave in TaTe${}_4$
• Charge order induced Dirac pockets in the nonsymmorphic crystal TaTe${}_4$
• Chiral phononic and electronic edge modes of EuPtSi
• Emergent Edge Modes in Shifted Quasi-One-Dimensional Charge Density Waves
• Gapless Topological Peierls-like instabilities in more than one dimension
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• Fermi Surface Reconstruction and Anisotropic Linear Magnetoresistance in the Charge Density Wave Topological Semimetal TaTe4
• Kramers nodal line in the charge density wave state of YTe${}_3$ and the influence of twin domains