Quantum theory of atomic layer materials

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740193
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics I
• Research Institution: Tohoku University
• Principal Investigator: MIKITO Koshino 東北大学, 理学(系)研究科(研究院), 准教授 (60361797)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: グラフェン / カーボンナノチューブ / 原子薄膜

Outline of Final Research Achievements

We theoretically studied the basic electronic properties of a wide variety of misoriented atomic layers, including graphene, boron-nitride and also multi-wall carbon
nanotubes. We developed an general effective theory to extract the relevant moire super-period by an appropriate coarse-graining process, and calculate the energy band structure, Landau level spectrum in magnetic field and the optical absorption spectra. In magnetic field, particularly, we found that the electron motion becomes highly complicated due to the co-existence of the cyclotron motion and periodic superstructure, giving rise to the fractal energy spectrum called Hofstadter’s butterfly. We demonstrate that moire superlattices arising in bilayer graphene coupled to hBN provide a periodic modulation with ideal length scales of the order of 10nm, and confirm the evidence of their recursive structure in the transport measurements.

Free Research Field

物性理論