Observation of surface superstructure induced by systematic vacancies in the topological Dirac semimetal Cd${}_3$As${}_2$

Abstract

The Dirac semimetal phase found in Cd${}_3$As${}_2$ is protected by a $C_4$ rotational symmetry derived from a corkscrew arrangement of systematic Cd vacancies in its complicated crystal structure. It is therefore surprising that no microscopic observation, direct or indirect, of these systematic vacancies has so far been described. To this end, we revisit the cleaved (112) surface of Cd${}_3$As${}_2$ using a combined approach of scanning tunneling microscopy and \textit{ab initio} calculations. We determine the exact position of the (112) plane at which Cd${}_3$As${}_2$ naturally cleaves, and describe in detail a structural periodicity found at the reconstructed surface, consistent with that expected to arise from the systematic Cd vacancies. This reconciles the current state of microscopic surface observations with those of crystallographic and theoretical models, and demonstrates that this vacancy superstructure, central to the preservation of the Dirac semimetal phase, survives the cleavage process and retains order at the surface.

arXiv commentSupplemental Material included. 16 pages, 7 figures

References in corpus (24)

• The electronic properties of graphene
• Topological Insulators
• Discovery of a Three-dimensional Topological Dirac Semimetal, Na3Bi
• 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
• Ultrahigh mobility and giant magnetoresistance in the Dirac semimetal Cd${}_3$As${}_2$
• Observation of a topological 3D Dirac semimetal phase in high-mobility Cd3As2
• Experimental Realization of a Three-Dimensional Dirac Semimetal
• Recent developments in transport phenomena in Weyl semimetals
• Quantum Oscillations from Surface Fermi-Arcs in Weyl and Dirac Semi-Metals
• Landau Quantization and Quasiparticle Interference in the Three-Dimensional Dirac Semimetal Cd3As2
• Quantum transport evidence for a three-dimensional Dirac semimetal phase in Cd3As2
• Giant negative magnetoresistance induced by the chiral anomaly in individual Cd3As2 nanowires
• Transport evidence for Fermi-arc mediated chirality transfer in the Dirac semimetal Cd${}_3$As${}_2$
• Observation of superconductivity in 3D Dirac semimetal Cd3As2 crystal
• Large linear magnetoresistance in Dirac semi-metal Cd3As2 with Fermi surfaces close to the Dirac points
• Cd3As2 is Centrosymmetric
• Unconventional Superconductivity at Mesoscopic Point-contacts on the 3-Dimensional Dirac Semi-metal Cd${}_3$As${}_2$
• Landau level splitting in Cd3As2 under high magnetic fields
• Helical Fermi arcs and surface states in time-reversal invariant Weyl semimetals
• Current at a distance and resonant transparency in Weyl semimetals
• Quantum oscillation and nontrivial transport in the Dirac Semimetal Cd3As2 nanodevice
• Large transverse Hall-like signal in topological Dirac semimetal Cd3As2

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