Precise Measurement of the Conductivity and Thermoelectric Power of the Quantum Hall Systems with Artificially Designed Modulation

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400311
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: The University of Tokyo
• Principal Investigator: Endo Akira 東京大学, 物性研究所, 助教 (20260515)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 量子ホール効果 / 高周波伝導率 / 熱起電力 / ２次元電子系 / エッジマグネトプラズモン / 電子固体相 / エピタクシャグラフェン

Outline of Final Research Achievements

rf conductivity and thermoelectric power of the quantum Hall systems have been measured employing coplanar waveguides. By intentionally introducing edges to the sample with a negative gate bias, the resonant peaks we had previously discovered in the quantum Hall regime have been found to be unambiguously attributable to the edge-magnetoplasmon excitation. The gate-bias dependence of the resonant frequency has been explained by capacitive coupling between the edge state and the gate.
We have also measured low-temperature magnetoresistance of the epitaxial graphene. By detailed analysis of the magnetoresistance traces, we deduced the effect of the steps in the SiC substrate, and also the ratio of the areas of the single- to bi-layer graphene for samples simultaneously containing the two types of areas.

Free Research Field

低次元電子系物性実験