Observation of Effective Pseudospin Scattering in ZrSiS

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 $\hslash v_F=2.65\pm 0.10$ eV Å in the Γ-M direction ~300 meV above the Fermi energy $E_F$, and the line node to be ~140 meV above $E_F$. More importantly, we find that certain scatterers can introduce energy-dependent non-preservation of pseudospins, giving rise to effective scattering between states with opposite valley 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.

References in corpus (2)

• Topological Semimetals
• Quasiparticle interference from magnetic impurities

Cited by in corpus (15)

• Atomically Thin Quantum Spin Hall Insulators
• Weak antilocalization in a noncentrosymmetric CaAgBi single crystal
• Determination of the Fermi surface and field-induced quasi-particle tunneling around the Dirac nodal-loop in ZrSiS
• Nodal-line semimetals from Weyl superlattices
• Evidence for bulk nodal loops and universality of Dirac-node arc surface states in ZrGeXc (Xc = S, Se, Te)
• Observation of gapless nodal-line states in NdSbTe
• Anisotropic Berry phase in the Dirac nodal-line semimetal ZrSiS: The effect of spin-orbit coupling
• Magneto-optical probe of the fully gapped Dirac band in ZrSiS
• Effect of mechanical strain on the optical properties of nodal-line semimetal ZrSiS
• Electron-phonon interaction and zero-field charge carrier transport in the nodal-line semimetal ZrSiS
• Symmetry-selective quasiparticle scattering and electric field tunability of the ZrSiS surface electronic structure
• Quasiparticle interference observation of the topologically non-trivial drumhead surface state in ZrSiTe
• Dirac Nodal Line and Rashba Splitting Surface States in Nonsymmorphic ZrGeTe
• Valley polarization of Landau levels driven by residual strain in the ZrSiS surface band
• Real-space visualization of quasiparticle dephasing near the Planckian limit in the Dirac line node material ZrSiS