English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Novel quantum phenomena, including high-temperature superconductivity,topological properties, and charge/spin density waves, appear inlow-dimensional conductive materials. It is possible to artificially createlow-dimensional systems by fabricating ultrathin films, quantum wires, orquantum dots with flat interfaces. Some experiments have been performed onultrathin compounds of strongly correlated electron systems. However, since itis technically difficult to control multiple elements precisely, most of theproperties of artificially fabricated low-dimensional compounds fall intouncharted territory. Here we show that extraordinary metal-insulatortransitions that oscillate depending on the scale occur in CaRuO_3 films with athickness of around several unit cells. We grow high-crystalline CaRuO_3ultrathin films, whose surface roughness is controlled at 199 pm, by molecularbeam epitaxy. We observe that resistivity oscillates with a magic thickness of25 {\AA}, which changes by 3 and 9 orders of magnitude at room temperature andat low temperature, respectively. These changes are much larger than quantumsize effects. We also confirm the same periodicity with photoelectronspectroscopy by etching the ultrathin film. Considering the large energy,periodicity and anisotropy, we conclude that the oscillating transitionsoriginate from the commensurability of Mott insulation triggered by Peierlsinstability arising from a dual restriction on the dimensions in wavenumberspace and real space. We have shown the possibility of producing new functionalmaterials by controlling film thickness on electron correlated compounds at thepicometer level.

Magic thickness of 25 {\AA} makes periodic metal-insulator transitions