Three-dimensional Pentagon Carbon with a genesis of emergent fermions

Abstract

Carbon, the basic building block of our universe, enjoys a vast number of allotropic structures. Owing to its bonding characteristic, most carbon allotropes possess the motif of hexagonal rings. Here, with first-principles calculations, we discover a new metastable three-dimensional carbon allotrope entirely composed of pentagon rings. The unique structure of this "Pentagon Carbon" leads to extraordinary electronic properties, making it a cornucopia of emergent topological fermions. Under lattice strain, Pentagon Carbon exhibits topological phase transitions, generating a series of novel quasiparticles, from isospin-1 triplet fermions, to triply-degenerate fermions, and further to concatenated Weyl-loop fermions. Its Landau level spectrum also exhibits distinct features, including a huge number of almost degenerate chiral Landau bands, implying pronounced magneto-transport signals. Our work not only discovers a remarkable carbon allotrope with highly rare structural motifs, it also reveals a fascinating hierarchical particle genesis with novel topological fermions beyond the Dirac and Weyl paradigm.

References in corpus (3)

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Cited by in corpus (8)

• Quantum Transport in Topological Semimetals under Magnetic Fields
• From Type-II Triply Degenerate Nodal Points and Three-Band Nodal Rings to Type-II Dirac Points in Centrosymmetric Zirconium Oxide
• Hexagonal supertetrahedral boron: A topological metal with multiple spin-orbit-free emergent fermions
• Engineering topological phases with a three-dimensional nodal-loop semimetal
• Chaos based Berry phase detector
• Interlocking nodal chains and their examples in carbon networks
• Anomalous in-gap edge states in two-dimensional pseudospin-1 Dirac insulators
• Emergence of Type-I and Type-II Dirac line nodes in penta-octa-graphene