Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 13: Semiconductor substrates: Adsorption
O 13.1: Vortrag
Montag, 22. März 2010, 15:00–15:15, H34
metallic transport and Anderson localization on In atomic layers on silicon — •Shiro Yamazaki1, Yoshikazu Hosomura2, Iwao Matsuda3, Rei Hobara2, Toyoaki Eguchi3, Yukio Hasegawa3, and Shuji Hasegawa2 — 1Institute of Applied Physics, University of Hamburg, Hamburg, Germany — 2Department of Physics, The University of Tokyo, Tokyo, Japan — 3The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Japan
Metallic electrical transport have not been observed in atomic-scale low-dimensional metal systems at low temperature region due to Anderson localization effect, except to Graphene or extremely conductive polyaniline [1,2]. Si(111)-√7× √3-In surface reconstruction is a In atomic layer supported by Si(111) substrate. According to ARPES study, the surface shows 2D metal state with the very large Fermi wave number (kF=14[nm−1]) and the large electron density (4.6×1014 [eV−1 cm−2]) [3], leading to a low resistance. By using variable-temperature micro-four-point probe method [3], very low resistance and metallic transport was found down to 10 K. It is quantitatively explained by the ARPES result by using 2D Boltzmann equation R2D=4 π2 λ m*/e2 ℏ kF2kB T. By introducing defects, it shows semiconducting temperature dependence of variable range hopping due to Anderson localization. [1]K. S. Novoselov, et al. , Nature 438, 197 (2005) [2]K. Lee, et al. , Nature 441, 65 (2006) [3]E. Rotenberg, et al. , Phys. Rev. Lett. 91, 246404 (2003) [4]T. Tanikawa, et al. , e-J. Surf. Sci. Nanotech. 1, 50 (2003)