Mott insulators appearing at thickness period corresponding to nesting in CaRuO_3

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Sakoda, M., Nobukane, H., Shimoda, S., Ichimura, K.
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910844658384896
author Sakoda, M.
Nobukane, H.
Shimoda, S.
Ichimura, K.
author_facet Sakoda, M.
Nobukane, H.
Shimoda, S.
Ichimura, K.
contents The typical material bismuth shows a several-fold change in electrical resistivity at 4 K over a 400 Å film thickness period. In 2021, we discovered a novel size effect with a period of 25 Å on strongly correlated compound CaRuO_3. The change in film thickness of only one nanometer leads to an increase in electrical resistivity at 4 K by a factor of several billion. However, the excitation energy of 2.4 eV on insulating CaRuO_3 is too large to explain the mechanism by conventional quantum well. In this study, we clarify that the increases in electrical resistivity are accompanied by lattice expansion and caused by the Mott transitions. We measured in-plane X-ray diffraction on CaRuO_3 films and found a 24.8 Å periodic thickness oscillation of the lattice spacing d_{(004)}. We determined the nesting vector from the Fermi surface and revealed the spin density wave with a period equivalent to the size effect. We concluded that the antiferromagnetic correlation appearing in the boundary conditions triggers the periodic Mott insulators depending on the film thickness.
format Preprint
id arxiv_https___arxiv_org_abs_2408_02996
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Mott insulators appearing at thickness period corresponding to nesting in CaRuO_3
Sakoda, M.
Nobukane, H.
Shimoda, S.
Ichimura, K.
Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
The typical material bismuth shows a several-fold change in electrical resistivity at 4 K over a 400 Å film thickness period. In 2021, we discovered a novel size effect with a period of 25 Å on strongly correlated compound CaRuO_3. The change in film thickness of only one nanometer leads to an increase in electrical resistivity at 4 K by a factor of several billion. However, the excitation energy of 2.4 eV on insulating CaRuO_3 is too large to explain the mechanism by conventional quantum well. In this study, we clarify that the increases in electrical resistivity are accompanied by lattice expansion and caused by the Mott transitions. We measured in-plane X-ray diffraction on CaRuO_3 films and found a 24.8 Å periodic thickness oscillation of the lattice spacing d_{(004)}. We determined the nesting vector from the Fermi surface and revealed the spin density wave with a period equivalent to the size effect. We concluded that the antiferromagnetic correlation appearing in the boundary conditions triggers the periodic Mott insulators depending on the film thickness.
title Mott insulators appearing at thickness period corresponding to nesting in CaRuO_3
topic Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2408.02996