Yoon H S, Park S J, Lee J E, Whang C N, Lyo I-W
Atomic-scale Surface Science Research Center and Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea.
Phys Rev Lett. 2004 Mar 5;92(9):096801. doi: 10.1103/PhysRevLett.92.096801. Epub 2004 Mar 2.
A one-dimensional system of Si(111)-(5 x 2)-Au is explored using scanning tunneling microscopy and spectroscopy. The chain of Si adatoms called bright protrusions (BP's) is found to be semiconducting with an evanescent state in the gap, which originates from adjoining metallic BP-free segments. A quantitative analysis shows that the evanescent state decays in inverse-Gaussian form, leading to an appearance of a parabolic BP chain, and scales to its chain length. Spatial decay of the state suggests a quadratic band bending and the existence of a Schottky-like potential barrier at the interface driven by charge transfer.
利用扫描隧道显微镜和光谱学对Si(111)-(5×2)-Au一维系统进行了研究。发现被称为亮突起（BP）的硅 adatoms 链在能隙中具有一个衰逝态，呈半导体性质，该衰逝态源于相邻的无金属BP段。定量分析表明，衰逝态以反高斯形式衰减，导致抛物线形BP链的出现，并与其链长成比例。该态的空间衰减表明存在二次能带弯曲以及由电荷转移驱动的界面处类似肖特基的势垒。
