Neobvyklé korelace elektronů v NaxCoO2 způsobené kvazidegenerovaností spinových stavů kobaltových iontů

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F08%3A00027725" target="_blank" >RIV/00216224:14310/08:00027725 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Unusual Electron Correlations in NaxCoO2 Due to the Spin-State Quasidegeneracy of Cobalt Ions

Popis výsledku v původním jazyce

Recent studies exposed many remarkable properties of layered cobaltates NaxCoO2. Surprisingly, many-body effects have been found to increase at sodium-rich compositions of NaxCoO2 where one expects a simple, nearly free motion of the dilute S=1/2 holes doped into a band insulator NaCoO2. Here we discuss the origin of enigmatic correlations that turn a doped NaCoO2 into a strongly correlated electronic system. A minimal model including orbital degeneracy is proposed and its predictions are discussed. Themodel is based on a key property of cobalt oxides - the spin-state quasidegeneracy of CoO6 octahedral complex - which has been known, e.g., in the context of an unusual physics of LaCoO3 compound. Another important ingredient of the model is the 90 Co-O-Co bonding in NaxCoO2 which allows nearest-neighbor t2g-eg hopping. This hopping introduces a dynamical mixture of electronic configurations t2g6,S=0 and t2g5eg1,S=1 of neighboring cobalt ions. We show that scattering of charge carriers

Název v anglickém jazyce

Unusual Electron Correlations in NaxCoO2 Due to the Spin-State Quasidegeneracy of Cobalt Ions

Popis výsledku anglicky

Recent studies exposed many remarkable properties of layered cobaltates NaxCoO2. Surprisingly, many-body effects have been found to increase at sodium-rich compositions of NaxCoO2 where one expects a simple, nearly free motion of the dilute S=1/2 holes doped into a band insulator NaCoO2. Here we discuss the origin of enigmatic correlations that turn a doped NaCoO2 into a strongly correlated electronic system. A minimal model including orbital degeneracy is proposed and its predictions are discussed. Themodel is based on a key property of cobalt oxides - the spin-state quasidegeneracy of CoO6 octahedral complex - which has been known, e.g., in the context of an unusual physics of LaCoO3 compound. Another important ingredient of the model is the 90 Co-O-Co bonding in NaxCoO2 which allows nearest-neighbor t2g-eg hopping. This hopping introduces a dynamical mixture of electronic configurations t2g6,S=0 and t2g5eg1,S=1 of neighboring cobalt ions. We show that scattering of charge carriers

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

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Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2008

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Progress of Theoretical Physics Supplement

ISSN

0375-9687

e-ISSN

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Svazek periodika

176

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

JP - Japonsko

Počet stran výsledku

27

Strana od-do

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Kód UT WoS článku

000263348100005

EID výsledku v databázi Scopus

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