Observation of disorder-induced 2D Mott-Hubbard states of the alkali-earth metal (Mg,Ba)-adsorbed Si(111) surface

被引：12

作者：

Ahn, JR

Lee, SS

Kim, ND

Min, JH

Hwang, CG

Chung, JW

机构：

[1] Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea

[2] Pohang Univ Sci & Technol, Basic Sci Res Inst, Pohang 790784, South Korea

来源：

PHYSICAL REVIEW LETTERS | 2000年 / 84卷 / 08期

关键词：

D O I：

10.1103/PhysRevLett.84.1748

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report evidence of a disorder-driven Mott-Hubbard-type localization on the alkali-earth metal (AEM) (Mg,Ba)-adsorbed Si(111)-(7 X 7) surface. The clean metallic Si(111) surface is found to undergo a two-dimensional (2D) metal-insulator transition as randomly distributed AEM adsorbates cause disorder on the surface. A well-defined electron-energy-loss peak unique to the insulating phase is attributed to an interband excitation between the split Hubbard bands originated from a metallic surface band at Fermi energy. A quantitative analysis of the loss peak reveals that the AEM-induced insulating surfaces are of a Mott-Hubbard type driven essentially by disorder.

引用

页码：1748 / 1751

页数：4