@article{oai:ynu.repo.nii.ac.jp:00004247,
 author = {Yokota, K and Takeda, J and Dang, C and Han, G and McCarthy, D.N. and Nagao, T and Hishita, S and Kitajima, M and Katayama, I},
 journal = {Applied physics letters},
 month = {},
 note = {application/pdf, Dynamical response of surface metallic states in single crystalline ultrathin Bi(001) films onSi(111) 7 7 surface was investigated at a spectral range of 0.1-12 THz by broadband terahertz time-domain spectroscopy. The observed transmittance increased with a decrease in the thickness, without showing a gap structure. The measured complex dielectric dispersion was analyzed using a Drude model, and the plasma frequency (xp) and damping constant (c) were found to be inversely proportional to the thickness. The results strongly indicate the existence of surface metallic states, whose carrier density and damping constant are estimated to be 3.08 1019 cm 3 and 4.83 102 THz, respectively.},
 title = {Surface metallic states in ultrathin Bi(001) films studied with terahertz time-domain spectroscopy},
 volume = {100},
 year = {2012}
}