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Title: Low-lying quasiparticle states and hidden collective chargeinstabilities in parent cobabltate superconductors

Abstract

We report a state-of-the-art photoemission (angle-resolvedphotoemission spectroscopy) study of high quality single crystals of theNaxCoO2 series focusing on the fine details of the low-energy states. TheFermi velocity is found to be small (<0.5 eV Angstrom) and only weaklyanisotropic over the Fermi surface at all dopings, setting the size ofthe pair wave function to be on the order of 10 20 nm. In the low-dopingregime, the exchange interlayer splitting vanishes and two-dimensionalcollective instabilities such as 120 degree-type fluctuations becomekinematically allowed. Our results suggest that the unusually small Fermivelocity and the unique symmetry of kinematic instabilities distinguishcobaltates from most other oxide superconductors.

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
COLLABORATION - PrincetonUniversity
OSTI Identifier:
903503
Report Number(s):
LBNL-61168
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US0703277
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Related Information: Journal Publication Date: 06/01/2006
Country of Publication:
United States
Language:
English
Subject:
75; FERMI LEVEL; FLUCTUATIONS; FOCUSING; MONOCRYSTALS; OXIDES; PHOTOEMISSION; SPECTROSCOPY; SUPERCONDUCTORS; SYMMETRY; VELOCITY; WAVE FUNCTIONS; Fermi surface; spin density waves; photoemission; superconducting materials; sodium compounds; potassium compounds advancedlight source als

Citation Formats

Qian, D., Hsieh, D., Wray, L., Chuang, Y-D., FEDOROV, A.V., Wu,D., Luo, J.L., Wang, N.L., Viciu, L., Cava, R.J., and Hasan, M.Z.. Low-lying quasiparticle states and hidden collective chargeinstabilities in parent cobabltate superconductors. United States: N. p., 2005. Web.
Qian, D., Hsieh, D., Wray, L., Chuang, Y-D., FEDOROV, A.V., Wu,D., Luo, J.L., Wang, N.L., Viciu, L., Cava, R.J., & Hasan, M.Z.. Low-lying quasiparticle states and hidden collective chargeinstabilities in parent cobabltate superconductors. United States.
Qian, D., Hsieh, D., Wray, L., Chuang, Y-D., FEDOROV, A.V., Wu,D., Luo, J.L., Wang, N.L., Viciu, L., Cava, R.J., and Hasan, M.Z.. Tue . "Low-lying quasiparticle states and hidden collective chargeinstabilities in parent cobabltate superconductors". United States. doi:.
@article{osti_903503,
title = {Low-lying quasiparticle states and hidden collective chargeinstabilities in parent cobabltate superconductors},
author = {Qian, D. and Hsieh, D. and Wray, L. and Chuang, Y-D. and FEDOROV, A.V. and Wu,D. and Luo, J.L. and Wang, N.L. and Viciu, L. and Cava, R.J. and Hasan, M.Z.},
abstractNote = {We report a state-of-the-art photoemission (angle-resolvedphotoemission spectroscopy) study of high quality single crystals of theNaxCoO2 series focusing on the fine details of the low-energy states. TheFermi velocity is found to be small (<0.5 eV Angstrom) and only weaklyanisotropic over the Fermi surface at all dopings, setting the size ofthe pair wave function to be on the order of 10 20 nm. In the low-dopingregime, the exchange interlayer splitting vanishes and two-dimensionalcollective instabilities such as 120 degree-type fluctuations becomekinematically allowed. Our results suggest that the unusually small Fermivelocity and the unique symmetry of kinematic instabilities distinguishcobaltates from most other oxide superconductors.},
doi = {},
journal = {Physical Review Letters},
number = ,
volume = 96,
place = {United States},
year = {Tue Dec 27 00:00:00 EST 2005},
month = {Tue Dec 27 00:00:00 EST 2005}
}
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