Thickness-induced metal to insulator transition in Ru nanosheets probed by photoemission spectroscopy: Effects of disorder and Coulomb interaction

Daiki Ootsuki, Kenjiro Kodera, Daiya Shimonaka, Masashi Arita, Hirofumi Namatame, Masaki Taniguchi, Makoto Minohara, Koji Horiba, Hiroshi Kumigashira, Eiji Ikenaga, Akira Yasui, Yoshiharu Uchimoto, Satoshi Toyoda, Masahito Morita, Katsutoshi Fukuda, Teppei Yoshida

Research output: Contribution to journalArticle

Abstract

We investigated the electronic structures of mono- and few-layered Ru nanosheets (N layers (L) with N = 1, ~6, and ~9) on Si substrate by ultra-violet and x-ray photoemission spectroscopies. The spectral density of states (DOS) near EF of ~6 L and 1 L is suppressed as it approaches EF in contrast to that of ~9 L, which is consistent with the Ru 3 d core-level shift indicating the reduction of the metallic conductivity. A power law g(ε) ∝ |ε − εF|α well reproduces the observed spectral DOS of ~6 L and 1 L. The evolution of the power factor α suggests that the transition from the metallic state of ~9 L to the 2-dimensional insulating state with the soft Coulomb gap of 1 L through the disordered 3-dimensional metallic state of ~6 L.

Original languageEnglish
Article number1541
JournalScientific reports
Volume10
Issue number1
DOIs
Publication statusPublished - 2020 Dec 1
Externally publishedYes

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Thickness-induced metal to insulator transition in Ru nanosheets probed by photoemission spectroscopy: Effects of disorder and Coulomb interaction'. Together they form a unique fingerprint.

  • Cite this

    Ootsuki, D., Kodera, K., Shimonaka, D., Arita, M., Namatame, H., Taniguchi, M., Minohara, M., Horiba, K., Kumigashira, H., Ikenaga, E., Yasui, A., Uchimoto, Y., Toyoda, S., Morita, M., Fukuda, K., & Yoshida, T. (2020). Thickness-induced metal to insulator transition in Ru nanosheets probed by photoemission spectroscopy: Effects of disorder and Coulomb interaction. Scientific reports, 10(1), [1541]. https://doi.org/10.1038/s41598-020-58057-9