Energy-dependent spatial texturing of charge order in 1 T -CuxTiSe2
Abstract
We report a detailed study of the microscopic effects of Cu intercalation on the charge density wave (CDW) in 1 T -CuxTiSe2 . Scanning tunneling microscopy and spectroscopy reveal a unique, Cu-driven spatial texturing of the charge-ordered phase, with the appearance of energy-dependent CDW patches and sharp π -phase shift domain walls (π DWs ). The energy and doping dependencies of the patchwork are directly linked to the inhomogeneous potential landscape due to the Cu intercalants. They imply a CDW gap with unusual features, including a large amplitude, the opening below the Fermi level, and a shift to higher binding energy with electron doping. Unlike the patchwork, the π DWs occur independently of the intercalated Cu distribution. They remain atomically sharp throughout the investigated phase diagram and occur in both superconducting and nonsuperconducting specimens. These results provide unique atomic-scale insight into the CDW ground state, questioning the existence of incommensurate CDW domain walls and contributing to understanding its formation mechanism and interplay with superconductivity.
- Publication:
-
Physical Review B
- Pub Date:
- April 2019
- DOI:
- 10.1103/PhysRevB.99.155133
- Bibcode:
- 2019PhRvB..99o5133S