Exploring of low-dimensional honeycomb sheet of 14th group elements (Si, Ge)

2014 Fiscal Year Final Research Report

• Project/Area Number: 24241040
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanostructural science
• Research Institution: The University of Tokyo
• Principal Investigator: TAKAGI Noriaki 東京大学, 新領域創成科学研究科, 准教授 (50252416)
• Co-Investigator(Kenkyū-buntansha): ARAFUNE Ryuichi 物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, 独立研究者 (50360483) ; TSUKAHARA Noriyuki 東京大学, 大学院新領域創成科学研究科, 助教 (80535378)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: シリセン / 表面界面 / Dirac電子系 / シリコン / ハニカム構造

Outline of Final Research Achievements

We investigated geometric and electronic structures of tw-dimensional superstructures consisting of Si atoms on Ag(111) by using scanning tunneling microscopy, lo-energy electron diffraction, density functional theory calculations and etc. We observed several superstructures after depositing Si atoms on the Ag(111) substrate. We investigated in detail 4x4 superstructure which appears as a single phase. Geometric analysis by electron diffraction and theoretical calculations has shown that the 4x4 structure is a honeycomb lattice of Si atoms (it can be called as Silicene). We also found that the electronic structure is strongly modified comparing with that of freestanding silicene which shows Dirac fermion features because of the strong hybridization with the substrate electronic system. We theoretically demonstrated that metal substrate covered with a monolayer h-BN sheet provides a good stage to realize Dirac fermion silicene.

Free Research Field

表面科学