Observation of the nesting and defect-driven 1D incommensurate charge density waves phase in the 2D system

• Published in: Journal of physics. Condensed matter Vol. 31; no. 11; p. 115402
• Main Authors: Matetskiy, A V, Denisov, N V, Hsing, C R, Wei, C M, Zotov, A V, Saranin, A A
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 20.03.2019
• Subjects: 2D system; charge density wave; surface reconstruction
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/aaf9ea

We report on the low-temperature scanning tunneling microscopy/spectroscopy (STM/STS) study of the (Bi, Na)/Si(1 1 1) reconstruction that is known to possess Fermi surface with apparently good nesting. We found that defects on this surface produce a one-dimensional-like pattern with the periodicity of 8.2 0.4 that is incommensurate with the lattice period. The mapping analysis reveals an occurrence of the k-dependent branch associated with quasi-particle interference and the k-independent branch associated with the nesting vector connecting the parallel segments of the (Bi,Na)/Si(1 1 1) Fermi surface, the fingerprint of the charge-density-wave (CDW) phase. The STS data demonstrates that development of the CDW phase leads to reducing electron density of states at the Fermi level.