Anomalous Fermi pockets on Hund's metal surface of Sr2RuO4 induced by the correlation-enhanced spin-orbit coupling

Fuente: arXiv
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Main Authors: Kondo, Takeshi, Ochi, Masayuki, Akebi, Shuntaro, Dong, Yuyang, Taniguchi, Haruka, Maeno, Yoshiteru, Shin, Shik
Format: Preprint
Published: 2024
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author Kondo, Takeshi
Ochi, Masayuki
Akebi, Shuntaro
Dong, Yuyang
Taniguchi, Haruka
Maeno, Yoshiteru
Shin, Shik
author_facet Kondo, Takeshi
Ochi, Masayuki
Akebi, Shuntaro
Dong, Yuyang
Taniguchi, Haruka
Maeno, Yoshiteru
Shin, Shik
contents The electronic structure of the topmost layer in Sr2RuO4 in the close vicinity of the Fermi level is investigated by angle-resolved photoemission spectroscopy (ARPES) with a 7-eV laser. We find that the spin-orbit coupling (SOC) predicted as 100 meV by the density functional theory (DFT) calculations is enormously enhanced in a real material up to 250 meV, even more than that of bulk state (200 meV), by the electron-correlation effect increased by the octahedral rotation in the crystal structure. This causes the formation of highly orbital-mixing small Fermi pockets and reasonably explains why the orbital-selective Mott transition (OSMT) is not realized in perovskite oxides with crystal distortion. Interestingly, Hund's metal feature allows the quasiparticle generation only near EF, restricting the spectral gap opening derived by band hybridization within an extremely small binding energy (< 10 meV). Furthermore, it causes coherent-incoherent crossover, making the Fermi pockets disappear at elevated temperatures. The anomalous Fermi pockets are characterized by the dichotomy of the orbital-isolating Hund's coupling and the orbital-mixing SOC, which is key to understanding the nature of Sr2RuO4.
format Preprint
id arxiv_https___arxiv_org_abs_2406_13900
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Anomalous Fermi pockets on Hund's metal surface of Sr2RuO4 induced by the correlation-enhanced spin-orbit coupling
Kondo, Takeshi
Ochi, Masayuki
Akebi, Shuntaro
Dong, Yuyang
Taniguchi, Haruka
Maeno, Yoshiteru
Shin, Shik
Strongly Correlated Electrons
Materials Science
Superconductivity
The electronic structure of the topmost layer in Sr2RuO4 in the close vicinity of the Fermi level is investigated by angle-resolved photoemission spectroscopy (ARPES) with a 7-eV laser. We find that the spin-orbit coupling (SOC) predicted as 100 meV by the density functional theory (DFT) calculations is enormously enhanced in a real material up to 250 meV, even more than that of bulk state (200 meV), by the electron-correlation effect increased by the octahedral rotation in the crystal structure. This causes the formation of highly orbital-mixing small Fermi pockets and reasonably explains why the orbital-selective Mott transition (OSMT) is not realized in perovskite oxides with crystal distortion. Interestingly, Hund's metal feature allows the quasiparticle generation only near EF, restricting the spectral gap opening derived by band hybridization within an extremely small binding energy (< 10 meV). Furthermore, it causes coherent-incoherent crossover, making the Fermi pockets disappear at elevated temperatures. The anomalous Fermi pockets are characterized by the dichotomy of the orbital-isolating Hund's coupling and the orbital-mixing SOC, which is key to understanding the nature of Sr2RuO4.
title Anomalous Fermi pockets on Hund's metal surface of Sr2RuO4 induced by the correlation-enhanced spin-orbit coupling
topic Strongly Correlated Electrons
Materials Science
Superconductivity
url https://arxiv.org/abs/2406.13900