Three-dimensional honeycomb carbon: Junction line distortion and novel emergent fermions

Abstract

Carbon enjoys a vast number of allotropic forms, each possessing unique properties determined by the lattice structures and bonding characters. Here, based on first-principles calculations, we propose a new three-dimensional carbon allotrope--hC28. We show that hC28 possesses exceptional energetic, dynamical, thermal, and mechanical stability. It is energetically more stable than most other synthesized or proposed carbon allotropes. The material has a relatively small bulk modulus, but is thermally stable at temperatures as high as 2000 K. The structural, mechanical, x-ray diffraction, and electronic properties are systematically investigated. Particularly, we show that its low-energy band structure hosts multiple unconventional emergent fermions, including the quadratic-contact-point fermions, the birefringent Dirac fermions, and the triple-point fermions. We construct effective models to characterize each kind of fermions. Our work not only discovers a new carbon allotropic form, it also reveals remarkable mechanical and electronic properties for this new material, which may pave the way towards both fundamental studies as well as practical applications.

References in corpus (31)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Electronic Structure of Pyrochlore Iridates: From Topological Dirac Metal to Mott Insulator
• Classification of topological insulators and superconductors in three spatial dimensions
• CALYPSO: a method for crystal structure prediction
• Dirac semimetal and topological phase transitions in A3Bi (A=Na, K, Rb)
• Dirac semimetal in three dimensions
• Three Dimensional Dirac Semimetal and Quantum Transports in Cd3As2
• Beyond Dirac and Weyl fermions: Unconventional quasiparticles in conventional crystals
• Topological Node-Line Semimetal in Three Dimensional Graphene Networks
• Nodal-chain metals
• T-Carbon: A Novel Carbon Allotrope
• Experimental Observation of Three-Component 'New Fermions' in Topological Semimetal MoP
• Spin-orbit-free Weyl-loop and Weyl-point semimetals in a stable three-dimensional carbon allotrope
• Nodal surface semimetals: Theory and material realization
• Line of Dirac Nodes in Hyper-Honeycomb Lattices
• Dirac and Weyl Superconductors in Three Dimensions
• Topological Semimetals with Triply Degenerate Nodal Points in θ-phase Tantalum Nitride
• Node-Surface and Node-Line Fermions From Nonsymmorphic Lattice Symmetries
• Towards Three-Dimensional Weyl-SurfaceSemimetals in Graphene Networks
• Co-existence of Weyl Fermion and Massless Triply Degenerate Nodal Points
• Hourglass Dirac Chain Metal in Rhenium Dioxide
• Coexistence of four-band nodal rings and triply-degenerate nodal points in centrosymmetric metal diborides
• New fermions on the line in topological symmorphic metals
• Hybrid Dirac Semimetal in CaAgBi Materials Family
• Four superhard carbon allotropes: First-principle study
• Birefringent break up of Dirac fermions in a square optical lattice
• MUSE: Multi-algorithm collaborative crystal structure prediction
• Asymmetric spatial structure of zero modes for birefringent Dirac fermions
• Instabilities of a birefringent semi-metal