start-ver=1.4 cd-journal=joma no-vol=470 cd-vols= no-issue=S1 article-no= start-page=S637 end-page=S638 dt-received= dt-revised= dt-accepted= dt-pub-year=2010 dt-pub=201012 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Photoemission study of Ca-intercalated graphite superconductor CaC6 en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this work, we have performed resonant photoemission studies of Ca-intercalated graphite superconductor CaC6. Using photon energy of the Ca 2p-3d threshold, the photoemission intensity of the peak at Fermi energy (E-F) is resonantly enhanced. This result provides spectroscopic evidence for the existence of Ca 3d states at E-F, and strongly supports that Ca 3d state plays a crucial role for the superconductivity of this material with relatively high T-c. en-copyright= kn-copyright= en-aut-name=OkazakiHiroyuki en-aut-sei=Okazaki en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YoshidaRikiya en-aut-sei=Yoshida en-aut-mei=Rikiya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=IwaiKeisuke en-aut-sei=Iwai en-aut-mei=Keisuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NoamiKengo en-aut-sei=Noami en-aut-mei=Kengo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MuroTakayuki en-aut-sei=Muro en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=NakamuraTetsuya en-aut-sei=Nakamura en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=WakitaTakanori en-aut-sei=Wakita en-aut-mei=Takanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=MuraokaYuji en-aut-sei=Muraoka en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=HiraiMasaaki en-aut-sei=Hirai en-aut-mei=Masaaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=TomiokaFumiaki en-aut-sei=Tomioka en-aut-mei=Fumiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=TakanoYoshihiko en-aut-sei=Takano en-aut-mei=Yoshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=TakenakaAsami en-aut-sei=Takenaka en-aut-mei=Asami kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=ToyodaMasahiro en-aut-sei=Toyoda en-aut-mei=Masahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=OguchTamio en-aut-sei=Oguch en-aut-mei=Tamio kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=YokoyaTakayoshi en-aut-sei=Yokoya en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= affil-num=1 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=2 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=3 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=4 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=5 en-affil= kn-affil=Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8 affil-num=6 en-affil= kn-affil=Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8 affil-num=7 en-affil= kn-affil=Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency affil-num=8 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=9 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=10 en-affil= kn-affil=National Institute for Materials Science (NIMS) affil-num=11 en-affil= kn-affil=National Institute for Materials Science (NIMS) affil-num=12 en-affil= kn-affil=Faculty of Engineering, Oita University affil-num=13 en-affil= kn-affil=Faculty of Engineering, Oita University affil-num=14 en-affil= kn-affil=Department of Quantum Matter, Graduate School of Advanced Sciences of Matter (ADSM) affil-num=15 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University END start-ver=1.4 cd-journal=joma no-vol=470 cd-vols= no-issue=S1 article-no= start-page=S641 end-page=S643 dt-received= dt-revised= dt-accepted= dt-pub-year=2010 dt-pub=201012 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Angle-resolved photoemission study of Si electronic structure: Boron concentration dependence en-subtitle= kn-subtitle= en-abstract= kn-abstract=The boron concentration dependence of the Si electronic structure of Si(100)2 ~ 1 surfaces were investigated by angle-resolved photoemission spectroscopy (ARPES). The ARPES spectra exhibit rigid shifts toward lower binding energy as the boron concentration increases. The band dispersion was obtained from fitting procedure, and it is found that the top of the valence band does not exceed the Fermi level even with a boron concentration 35 times larger than the critical concentration of the metal-insulator transition. en-copyright= kn-copyright= en-aut-name=WakitaTakanori en-aut-sei=Wakita en-aut-mei=Takanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OkazakiHiroyuki en-aut-sei=Okazaki en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakanoYoshihiko en-aut-sei=Takano en-aut-mei=Yoshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=HiraiMasaaki en-aut-sei=Hirai en-aut-mei=Masaaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MuraokaYuji en-aut-sei=Muraoka en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=YokoyaTakayoshi en-aut-sei=Yokoya en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil= kn-affil=Research Laboratory for Surface Science (RLSS), Okayama University affil-num=2 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=3 en-affil= kn-affil=National Institute for Material Science (NIMS) affil-num=4 en-affil= kn-affil=Research Laboratory for Surface Science (RLSS), Okayama University affil-num=5 en-affil= kn-affil=Research Laboratory for Surface Science (RLSS), Okayama University affil-num=6 en-affil= kn-affil=Research Laboratory for Surface Science (RLSS), Okayama University END start-ver=1.4 cd-journal=joma no-vol=470 cd-vols= no-issue=S1 article-no= start-page=S389 end-page=S390 dt-received= dt-revised= dt-accepted= dt-pub-year=2010 dt-pub=201012 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Analysis on photoemission spectrum of superconducting FeSe en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this paper, we present the result of soft X-ray photoemission spectroscopy and its comparison with the density functional calculation. Although local density approximation seems to be a good starting point for describing the electronic structure of FeSe, the simulated spectrum poorly reproduced the structure around E(B) = 2 eV. This result suggests the necessity of theoretical treatment beyond local density approximation. en-copyright= kn-copyright= en-aut-name=YoshidaRikiya en-aut-sei=Yoshida en-aut-mei=Rikiya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=WakitaTakanori en-aut-sei=Wakita en-aut-mei=Takanori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=OkazakiHiroyuki en-aut-sei=Okazaki en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MizuguchiYoshikazu en-aut-sei=Mizuguchi en-aut-mei=Yoshikazu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TsudaShunsuke en-aut-sei=Tsuda en-aut-mei=Shunsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=TakanoYoshihiko en-aut-sei=Takano en-aut-mei=Yoshihiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=TakeyaHiroyuki en-aut-sei=Takeya en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=HirataKazuto en-aut-sei=Hirata en-aut-mei=Kazuto kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=KatoYukako en-aut-sei=Kato en-aut-mei=Yukako kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=MuroTakayuki en-aut-sei=Muro en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=OkawaMario en-aut-sei=Okawa en-aut-mei=Mario kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= en-aut-name=IshizakaKyoko en-aut-sei=Ishizaka en-aut-mei=Kyoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=12 ORCID= en-aut-name=ShinShik en-aut-sei=Shin en-aut-mei=Shik kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=13 ORCID= en-aut-name=HarimaHisatomo en-aut-sei=Harima en-aut-mei=Hisatomo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=14 ORCID= en-aut-name=HiraiMasaaki en-aut-sei=Hirai en-aut-mei=Masaaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=15 ORCID= en-aut-name=MuraokaYuji en-aut-sei=Muraoka en-aut-mei=Yuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=16 ORCID= en-aut-name=YokoyaTakayoshi en-aut-sei=Yokoya en-aut-mei=Takayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=17 ORCID= affil-num=1 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=2 en-affil= kn-affil=Research Laboratory for Surface Science (RLSS), Okayama University affil-num=3 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=4 en-affil= kn-affil=JST, Transformative Research-Project on Iron Pnictides (TRIP) affil-num=5 en-affil= kn-affil=JST, Transformative Research-Project on Iron Pnictides (TRIP) affil-num=6 en-affil= kn-affil=JST, Transformative Research-Project on Iron Pnictides (TRIP) affil-num=7 en-affil= kn-affil=National Institute for Material Science affil-num=8 en-affil= kn-affil=National Institute for Material Science affil-num=9 en-affil= kn-affil=Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8 affil-num=10 en-affil= kn-affil=Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8 affil-num=11 en-affil= kn-affil=Institute for Solid State Physics, The University of Tokyo affil-num=12 en-affil= kn-affil=Institute for Solid State Physics, The University of Tokyo affil-num=13 en-affil= kn-affil=Institute for Solid State Physics, The University of Tokyo affil-num=14 en-affil= kn-affil=JST, Transformative Research-Project on Iron Pnictides (TRIP) affil-num=15 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=16 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University affil-num=17 en-affil= kn-affil=The Graduate School of Natural Science and Technology, Okayama University en-keyword=Iron chalcogenide superconductor kn-keyword=Iron chalcogenide superconductor en-keyword=FeSe kn-keyword=FeSe en-keyword=Photoemission spectroscopy kn-keyword=Photoemission spectroscopy en-keyword=Band calculation kn-keyword=Band calculation END