Observation of Electronic Structure Modification in the Hidden Order Phase of CeCoSi

Fuente: arXiv
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Main Authors: Kimura, Shin-ichi, Watanabe, Hiroshi, Tatsukawa, Shingo, Tanida, Hiroshi
Format: Preprint
Published: 2023
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author Kimura, Shin-ichi
Watanabe, Hiroshi
Tatsukawa, Shingo
Tanida, Hiroshi
author_facet Kimura, Shin-ichi
Watanabe, Hiroshi
Tatsukawa, Shingo
Tanida, Hiroshi
contents CeCoSi with no local inversion symmetric crystal structure ($P4/nmm$) exhibits a phase transition of unknown origin (Hidden Order: HO) at about 12 K ($T_0$) above the antiferromagnetic transition temperature ($T_{\rm N}=9.4$ K). The electronic structure change across $T_0$ was investigated with high-precision optical reflection spectroscopy. The optical spectrum changed from a typical metallic behavior above $T_0$ to a gap-like structure at around 15 meV below $T_0$. The gap-like structure was unchanged across $T_{\rm N}$ except for the narrowing of the Drude component of carriers due to the suppression of magnetic fluctuations. This result suggests a slight change from the typical metallic electronic structure above $T_0$ to that with an energy gap near the Fermi level in the HO phase. The change in electronic structure in the HO phase was concluded to be due to electron/valence instability.
format Preprint
id arxiv_https___arxiv_org_abs_2302_09749
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Observation of Electronic Structure Modification in the Hidden Order Phase of CeCoSi
Kimura, Shin-ichi
Watanabe, Hiroshi
Tatsukawa, Shingo
Tanida, Hiroshi
Strongly Correlated Electrons
CeCoSi with no local inversion symmetric crystal structure ($P4/nmm$) exhibits a phase transition of unknown origin (Hidden Order: HO) at about 12 K ($T_0$) above the antiferromagnetic transition temperature ($T_{\rm N}=9.4$ K). The electronic structure change across $T_0$ was investigated with high-precision optical reflection spectroscopy. The optical spectrum changed from a typical metallic behavior above $T_0$ to a gap-like structure at around 15 meV below $T_0$. The gap-like structure was unchanged across $T_{\rm N}$ except for the narrowing of the Drude component of carriers due to the suppression of magnetic fluctuations. This result suggests a slight change from the typical metallic electronic structure above $T_0$ to that with an energy gap near the Fermi level in the HO phase. The change in electronic structure in the HO phase was concluded to be due to electron/valence instability.
title Observation of Electronic Structure Modification in the Hidden Order Phase of CeCoSi
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2302.09749