Fully two-dimensional incommensurate charge modulation on the Pd-terminated polar surface of PdCoO2

Abstract

Here we use low-temperature scanning tunneling microscopy and spectroscopy to study the polar surfaces of PdCoO2. On the CoO2-terminated polar surface, we detect the quasiparticle interference pattern originating from the Rashba spin-split surface states. On the well-ordered Pd-terminated polar surface, we observe a regular lattice which has larger lattice constant than the atomic lattice of PdCoO2. In comparison with the shape of the hexagonal bulk Fermi surface, we identify this regular lattice as a fully two-dimensional incommensurate charge modulation that is driven by the Fermi surface nesting. More interestingly, we also find the moiré pattern induced by the interference between the two-dimensional incommensurate charge modulation in the Pd layer and the underlying CoO2 lattice. Our results not only show a new charge modulation on the Pd surface of PdCoO2, but also pave the way for fully understanding the novel electronic properties of this material.

12 pages, 4 figures

References in corpus (8)

• The properties of ultrapure delafossite metals
• Maximal Rashba-like spin splitting via kinetic energy-driven inversion symmetry breaking
• Critical behavior of the metallic triangular-lattice Heisenberg antiferromagnet PdCrO2
• Electron hydrodynamics with a polygonal Fermi surface
• Large anisotropic thermal conductivity of intrinsically two-dimensional metallic oxide PdCoO${}_2$
• Quasiparticle interference and quantum confinement in a correlated Rashba spin-split 2D electron liquid
• Tuneable electron-magnon coupling of ferromagnetic surface states in PdCoO${}_2$
• Finite-size effects of electron transport in PdCoO${}_2$

Cited by in corpus (3)

• Probing hidden Mott gap and incommensurate charge modulation on the polar surfaces of PdCrO${}_2$
• Adsorbate-induced formation of a surface-polarity-driven nonperiodic superstructure
• Coexistence of stripe order and superconductivity in NaAlSi