【公開日：2023.07.31】【最終更新日：2023.04.27】
課題データ / Project Data
課題番号 / Project Issue Number
22IT0047
利用課題名 / Title
半導体ナノデバイスにおける電子ダイナミクス研究2
利用した実施機関 / Support Institute
東京工業大学
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）加工・デバイスプロセス/Nanofabrication（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions（副 / Sub）-
キーワード / Keywords
Lithography
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
LIN CHAOJING
所属名 / Affiliation
Department of Physics, Tokyo Institute of Technology
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）技術代行/Technology Substitution（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
IT-001：電子ビーム露光装置
IT-037：クリーンルーム付帯設備一式
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
In cavity quantum electrodynamics, which studies the coherent coupling of fermions and bosons, it is important to construct a resonator with high impedance in order to obtain strong coupling. Since the plasmon in the quantum Hall system exhibits a high quantized impedance (12.9 kΩ at filling factor 2), strong coupling with a double quantum dot (DQD) charge qubit is expected. In this study, we formed a coupled plasmon resonator-DQD system and successfully observed plasmon-assisted tunneling in the DQD.
実験 / Experimental
【Equipment】Scanning Electron Microscope, Electron-beam
Lithography
【Methods】Figure (a) shows scanning electron microscope
pictures of the device and the measurement setup. The gate patterns (white
regions) were fabricated by first forming a resist pattern on an AlGaAs/GaAs
semiconductor heterostructure substrate using electron beam lithography and
then depositing thin metal films (Ti/Au). When a magnetic field of 3.6T is
applied to form a quantum Hall state with filling factor 2, the region defined
by the ring-shaped gate electrode forms an isolated circular quantum Hall
plasmon resonator. Applying a microwave of frequency f (= 2.95 GHz) to
the top electrode (Inj) excites a plasmon resonance mode (schematically shown
by the red and white wave packets). A gate defined double quantum dot (DQD) is
formed in the vicinity of the resonator and coupled to the resonator capacitively.
The samples were
measured using a dilution refrigerator in Fujisawa Laboratory at Tokyo
Institute of Technology.
結果と考察 / Results and Discussion
Figure (b) shows the tunneling current plotted with respect to the energy detuning ε of the two dots. Without applying a microwave, a single resonant tunneling peak (i) is observed, while two side peaks (ii) appear when applying a microwave at the resonance f = 2.95 GHz. We confirmed that the side peaks are due to plasmon-assisted tunneling with absorption (n = 1) and emission (n = -1) of plasmons by means of frequency-field dependence and power dependence. We also clarified how the plasmon resonance property changes reflecting the charge state in DQD by observing the high-frequency transmission characteristic S21.
図・表・数式 / Figures, Tables and Equations
Fig. 1 (a) SEM picture and measurement setup. (b) Resonant tunneling of DQD (i) and plasmon-assisted tunneling (ii).
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
This study was supported by the JSPS KAKENHI (JP19H05603), JST PRESTO (JPMJPR225C). The author acknowledges the experimental support from Ko Futamata (Tokyo Tech), and Masayuki Hashisaka, Takafumi Akiho, Koji Muraki (NTT BRL) and technical support from Takaaki Umemoto (Tokyo Tech).
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- Chaojing Lin, Ko Futamata, Masayuki Hashisaka, Takafumi Akiho, Koji Muraki, Toshimasa Fujisawa, "Plasmon assisted tunneling in a double quantum dot coupled to a quantum-Hall plasmon resonator", submitted for JPS meeting (to be held on March 22-25, 2023).
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件