Formation of isolated artificial two-level system in solid devices

固体器件中孤立人工二能级系统的形成

• 批准号: 10450014
• 负责人: ISHIBASHI Koji
• 金额: $ 9.15万
• 依托单位: The Institute of Physical and Chemical Research (RIKEN)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10450014/
• 关键词: quantum dots; coupled quantum dots; Coulomb blockade; zero-dimensional quantum level; carbon nanotubes; two-dimensional electron gas; 負性微分コンダクタンス; クーロンダイアモンド; クーロン振動; 単一電子エレクトロメータ

The aim of the project is to realize an artificial two-level system using coupled quantum dots, where the single electron charging effect (Coulomb blockade) and zero-dimensional quantum levels are important. To form the quantum dot, we first used surface gate technique, where the lithographically made surface gates are deposited on top of the GaAs/AlGaAs 2 dimensional electron gas wafer. The Coulomb blockade and zero-dimensional quantum levels have been clearly observed below 1 Kelvin in a single dots, and resonant tunneling between two discrete quantum levels in double dots have been observed with an important Coulomb blockade effect. But, coherence in the two-dot system is to be studied further. The signal of the change in single electron charge have been obtained in double-dot system, which is important for the read-out of the two level system.To increase the operation temperature of the coupled quantum dot, we have developed the process of the formation of quantum dots in single-wall carbon nanotubes which has an extremely small diameter of about one nanometer. The charging energy and the mean level spacing have been obtained which is larger by more than an order compared with the dot made by standard electron beam lithography. Finally, we have developed a technique to form coupled quantum dots in carbon nanotubes.

该项目的目的是使用耦合量子点实现人工两能级系统，其中单电子充电效应（库仑阻塞）和零维量子能级很重要。为了形成量子点，我们首先使用表面栅极技术，其中光刻制造的表面栅极沉积在GaAs/AlGaAs二维电子气晶片的顶部。在低于1开尔文的单点中已经清楚地观察到库仑阻塞和零维量子能级，并且在双点中已经观察到两个离散量子能级之间的共振隧穿，具有重要的库仑阻塞效应。但是，两点系统的相干性还有待进一步研究。为了提高耦合量子点的工作温度，我们研究了在直径约为1纳米的单壁碳纳米管中形成量子点的方法，并在双点系统中获得了单电子电荷变化的信号，这对二能级系统的读出具有重要意义。获得了比标准电子束光刻大一个数量级以上的充电能量和平均能级间距。最后，我们开发了一种在碳纳米管中形成耦合量子点的技术。

项目成果

K.Ishibashi, T.Ida, H.Kotani, Y.Ochiai, T.Sugano and Y.Aoyagi: "Characterization of SET electrometer coupled to the quantum dot in GaAs/AlGaAs 2DEG"Microelectronic Engineering.. 47. 185-187 (1999)

K.Ishibashi、T.Ida、H.Kotani、Y.Ochiai、T.Sugano 和 Y.Aoyagi：“与 GaAs/AlGaAs 2DEG 中量子点耦合的 SET 静电计的表征”微电子工程.. 47. 185-187 (

T.Aono,K.Ishibashi,Y.Aoyagi: "Phenomenological theory of Rabi oscillations in coupled quantum dots"Physica B. 272. 39-41 (2000)

T.Aono、K.Ishibashi、Y.Aoyagi：“耦合量子点中拉比振荡的现象学理论”Physica B. 272. 39-41 (2000)

K.Ishibashi, M.Suzuki, T.Ida, K.Tsukagoshi and Y.Aoyagi: "Quantum dots in carbon nanotubes"Jpn.J.Appl.Phys.. 39. 7053-7057 (2000)

K.Ishibashi、M.Suzuki、T.Ida、K.Tsukagoshi 和 Y.Aoyagi：“碳纳米管中的量子点”Jpn.J.Appl.Phys.. 39. 7053-7057 (2000)

Masaki Suzuki et al.: "Quantum dot formation in single-wall carbon nanotubes"Jpn.J.Appl.Phys.. 40・3B(掲載予定). (2001)

铃木正树等：“单壁碳纳米管中的量子点形成”Jpn.J.Appl.Phys.40·3B（待出版）（2001年）。

T.Aono, K.Ishibashi and Y.Aoyagi: "Phenomenological theory of the Rabi oscillations in coupled quantum dots"Physica B. 272. 39-41 (2000)

T.Aono、K.Ishibashi 和 Y.Aoyagi：“耦合量子点中拉比振荡的现象学理论”Physica B. 272. 39-41 (2000)