TY - JOUR
T1 - Laser-excited ultrahigh-resolution photoemission spectroscopy of superconducting Na0.35CoO2·1.3H2O
AU - Shimojima, T.
AU - Yokoya, T.
AU - Kiss, T.
AU - Chainani, A.
AU - Shin, S.
AU - Togashi, T.
AU - Zhang, C.
AU - Chen, C.
AU - Watanabe, S.
AU - Takada, K.
AU - Sasaki, T.
AU - Sakurai, H.
AU - Takayama-Muromachi, E.
N1 - Funding Information:
We thank S. Maekawa, W. Koshibae and Y. Yanase for their valuable discussion. We also thank F. Kanetaka for his help in PES measurements. This study was partially supported by CREST of Japan Science and Technology Agency (JST), and by Grants-in-Aid for Scientific Research (B) (16340111) and Young Scientists (A) (14702010) from Japan Society for the Promotion of Science.
PY - 2006/1
Y1 - 2006/1
N2 - We have studied the electronic structure near the Fermi level of the layered cobaltate superconductor Na0.35CoO2·1. 3H2O using laser-excited ultrahigh-resolution photoemission spectroscopy (PES). In the normal state, we observed the formation of a pseudogap with an energy scale of ∼20 meV. Across the superconducting transition, we observed the leading-edge shift at 3.5 K compared to that at 10 K, indicating superconducting gap (SC gap) opening having a gap value Δ of 0.5-0.7 meV. The energy scale of the SC gap is ∼20 times smaller than that of the pseudogap, suggesting the existence of competing order parameters at low temperatures.
AB - We have studied the electronic structure near the Fermi level of the layered cobaltate superconductor Na0.35CoO2·1. 3H2O using laser-excited ultrahigh-resolution photoemission spectroscopy (PES). In the normal state, we observed the formation of a pseudogap with an energy scale of ∼20 meV. Across the superconducting transition, we observed the leading-edge shift at 3.5 K compared to that at 10 K, indicating superconducting gap (SC gap) opening having a gap value Δ of 0.5-0.7 meV. The energy scale of the SC gap is ∼20 times smaller than that of the pseudogap, suggesting the existence of competing order parameters at low temperatures.
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U2 - 10.1016/j.jpcs.2005.10.124
DO - 10.1016/j.jpcs.2005.10.124
M3 - Article
AN - SCOPUS:33645017971
SN - 0022-3697
VL - 67
SP - 282
EP - 285
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
IS - 1-3
ER -