Absence of in-gap modes in charge density wave edge dislocations of the Weyl semimetal (TaSe${}_4$)${}_2$I

Abstract

Axion electrodynamics in condensed matter could emerge from the formation of charge density waves (CDWs) in Weyl semimetals. (TaSe${}_4$)${}_2$I was proposed to be the first material platform for realizing axionic CDW that may host topological defects with one-dimensional in-gap modes. The real-space modulation of the CDW phase and the existence of in-gap modes remain elusive. Here, we present a comprehensive scanning tunneling microscopic and spectroscopic study of a CDW on a (TaSe${}_4$)${}_2$I (110) surface. The tunneling spectroscopic measurements reveal a CDW gap of $\sim 200$ meV, in good agreement with prior studies, while the spectroscopy of CDW edge dislocation shows no indication of in-gap states. The bias-dependent scanning tunneling microscopy images indicate that the CDW in(TaSe${}_4$)${}_2$I is dominated by a large periodic lattice distortion instead of charge modulation, suggesting a non-Peierls mechanism of the CDW instability.

arXiv comment15 pages, 5 figures

References in corpus (19)

• Discovery of a Weyl Fermion Semimetal and Topological Fermi Arcs
• Experimental discovery of Weyl semimetal TaAs
• Theory of Intertwined Orders in High Temperature Superconductors
• Observation of Weyl nodes in TaAs
• Fermi surface nesting and the origin of Charge Density Waves in metals
• Topological quantum properties of chiral crystals
• Chiral anomaly, Charge Density Waves, and Axion Strings from Weyl Semimetals
• Evidence for an axionic charge density wave in the Weyl semimetal (TaSe4)2I
• Quasiparticle interference of the Fermi arcs and surface-bulk connectivity of a Weyl semimetal
• A Charge-Density-Wave Topological Semimetal
• Type-III Weyl Semimetals: (TaSe4)2I
• Magnetic catalysis and axionic charge-density-wave in Weyl semimetals
• Microscopic evidence for strong periodic lattice distortion in 2D charge-density wave systems
• Insight into the charge density wave gap from contrast inversion in topographic STM images
• Electronic Instability in a Zero-Gap Semiconductor: the Charge-Density Wave in (TaSe4)2I
• Axionic Band Topology in Inversion-Symmetric Weyl-Charge-Density Waves
• Surface Charge Induced Dirac Band Splitting in a Charge Density Wave Material (TaSe4)2I
• Dynamical Piezomagnetic Effect in Time-Reversal Invariant Weyl Semimetals with Axionic Charge-Density Waves
• Kramers-Weyl fermions in the chiral charge density wave material (TaSe${}_4$)${}_2$I

Cited by in corpus (5)

• Charge Density Wave and Ferromagnetism in Intercalated CrSBr
• Discovery of a Topological Charge Density Wave
• Memristive switching in the surface of a charge-density-wave topological semimetal
• Emergent Edge Modes in Shifted Quasi-One-Dimensional Charge Density Waves
• Emergent Weyl-like points in periodically modulated systems