Electron transport through site-controlled single quantum dots/rings and its applications

2015 Fiscal Year Final Research Report

• Project/Area Number: 25246004
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanostructural physics
• Research Institution: The University of Tokyo
• Principal Investigator: Hirakawa Kazuhiko 東京大学, 生産技術研究所, 教授 (10183097)
• Co-Investigator(Renkei-kenkyūsha): SHIBATA Kenji 東北工業大学, 工学部, 准教授 (00436578) ; OIWA Akira 大阪大学, 産業科学研究所, 教授 (10321902) ; YOH Kanji 北海道大学, 量子集積エレクトロニクス研究センター, 教授 (60220539)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 量子ドット / テラヘルツ / 単一電子トランジスタ / ナノ構造

Outline of Final Research Achievements

The orbital quantization energies and electron energies in self-assembled InAs quantum dots lie in the energy range of terahertz photons. However, since the quantum dots are by far smaller than the terahertz wavelength, the conventional terahertz transmission spectroscopy cannot obtain signals from the quantum dots. In this work, we have developed a novel spectroscopy technique for single quantum dots; we have tightly focused terahertz radiation on a single quantum dot by using the source/drain electrodes of the single quantum dot transistor structure as a terahertz antenna and measured terahertz-induced photocurrent through the quantum dot. From such measurements, we have determined important parameters on the electronic structures of the quantum dots, such as orbital quantization energies and electron charging energies.

Free Research Field

量子半導体エレクトロニクス