Lee S S, Ahn J R, Kim N D, Min J H, Hwang C G, Chung J W, Yeom H W, Ryjkov Serguei V, Hasegawa Shuji
Physics Department and Basic Science Research Institute, Pohang University of Science and Technology, San 31 Hyoja Dong, Pohang 790-784, Korea.
Phys Rev Lett. 2002 May 13;88(19):196401. doi: 10.1103/PhysRevLett.88.196401. Epub 2002 Apr 24.
We find that foreign adsorbates acting as local impurities can induce a metal-insulator transition by pinning a charge-density wave (CDW) on the quasi-1D metallic In/Si(111)-(4x1) chain system. Our scanning tunneling microscopy image clearly reveals the presence of a new local 4x2 structure nucleated by Na adatoms at room temperature, which turns out to be insulating with a doubled periodicity along the chains. We directly determine a CDW gap energy Delta = 105+/-8 meV by identifying a characteristic loss peak in our high-resolution electron-energy-loss spectra. We thus report the first observation of a local impurity-derived Peierls-like reconstruction of a quasi-1D system.
我们发现，作为局域杂质的外来吸附质可以通过在准一维金属In/Si(111)-(4x1)链系统上钉扎电荷密度波（CDW）来诱导金属-绝缘体转变。我们的扫描隧道显微镜图像清楚地揭示了在室温下由Na吸附原子成核的新的局域4x2结构的存在，结果表明该结构沿链具有加倍的周期性且呈绝缘性。通过在我们的高分辨率电子能量损失谱中识别出一个特征损失峰，我们直接确定了CDW能隙能量Δ = 105±8 meV。因此，我们报告了首次观察到准一维系统中由局域杂质衍生的类佩尔斯重构。
