Observation of Effective Pseudospin Scattering in ZrSiS

Michael S. Lodge, Guoqing Chang, Cheng Yi Huang, Bahadur Singh, Jack Hellerstedt, Mark T. Edmonds, Dariusz Kaczorowski, Md Mofazzel Hosen, Madhab Neupane, Hsin Lin, Michael S. Fuhrer, Bent Weber, Masahiro Ishigami

Research output: Contribution to journalArticleResearchpeer-review

14 Citations (Scopus)

Abstract

3D Dirac semimetals are an emerging class of materials that possess topological electronic states with a Dirac dispersion in their bulk. In nodal-line Dirac semimetals, the conductance and valence bands connect along a closed path in momentum space, leading to the prediction of pseudospin vortex rings and pseudospin skyrmions. Here, we use Fourier transform scanning tunneling spectroscopy (FT-STS) at 4.5 K to resolve quasiparticle interference (QPI) patterns at single defect centers on the surface of the line nodal semimetal zirconium silicon sulfide (ZrSiS). Our QPI measurements show pseudospin conservation at energies close to the line node. In addition, we determine the Fermi velocity to be vF = 2.65 ± 0.10 eV Å in the Δ-M direction ∼300 meV above the Fermi energy EF and the line node to be ∼140 meV above EF. More importantly, we find that certain scatterers can introduce energy-dependent nonpreservation of pseudospin, giving rise to effective scattering between states with opposite pseudospin deep inside valence and conduction bands. Further investigations of quasiparticle interference at the atomic level will aid defect engineering at the synthesis level, needed for the development of lower-power electronics via dissipationless electronic transport in the future.

Original languageEnglish
Pages (from-to)7213-7217
Number of pages5
JournalNano Letters
Volume17
Issue number12
DOIs
Publication statusPublished - 13 Dec 2017

Keywords

  • Dirac line node semimetal
  • FT-STS
  • low-temperature scanning tunneling microscopy
  • quasiparticle interference spectroscopy
  • topological phases of matter

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