ZrOsSi: A $Z_2$ topological metal with a superconducting ground state

Abstract

The silicide superconductors (Ta, Nb, Zr)OsSi are among the best candidate materials for investigating the interplay of topological order and superconductivity. Here, we investigate in detail the normal-state topological properties of (Ta, Nb, Zr)OsSi, focusing on ZrOsSi, by employing a combination of ${}^{29}$Si nuclear magnetic resonance (NMR) measurements and first-principles band-structure calculations. We show that, while (Ta, Nb)OsSi behave as almost ideal metals, characterized by weak electronic correlations and a relatively low density of states, the replacement of Ta (or Nb) with Zr expands the crystal lattice and shifts ZrOsSi towards an insulator. Our ab initio calculations indicate that ZrOsSi is a $Z_2$ topological metal with clear surface Dirac cones and properties similar to a doped strong topological insulator.

15 pages, 9 figures

References in corpus (14)

• Topological Insulators with Inversion Symmetry
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal
• Computing topological invariants without inversion symmetry
• Kagome superconductors AV${}_3$Sb${}_5$ (A=K, Rb, Cs)
• Nonsymmorphic-symmetry-protected hourglass Dirac loop, nodal line, and Dirac point in bulk and monolayer $X_3$SiTe${}_6$ ($X=$ Ta, Nb)
• NMR Probe of Metallic States in Nanoscale Topological Insulators
• Spin-triplet superconductivity in Weyl nodal-line semimetals
• Topologically-Driven Linear Magnetoresistance in Helimagnetic FeP
• Dirac electron behavior and NMR evidence for topological band inversion in ZrTe5
• Dirac lines and loop at the Fermi level in the Time-Reversal Symmetry Breaking Superconductor LaNiGa${}_2$
• Time-Reversal Symmetry Breaking Superconductivity in Three-Dimensional Dirac Semimetallic Silicides
• ${}^{239}$Pu nuclear magnetic resonance in the candidate topological insulator PuB${}_4$
• Field induced charge symmetry in topological insulator Bi${}_2$Te${}_3$ revealed by nuclear magnetic resonance

Cited by in corpus (2)

• Dirac surface states, multiorbital dimerization and superconductivity in Nb- and Ta-based A15 compounds
• Signature of point nodal superconductivity in the Dirac semimetal PdTe