Basic Research on Silicon Quantum Computation Based on Isotope Control and Neutron Irradiation

基于同位素控制和中子辐照的硅量子计算基础研究

• 批准号: 13305025
• 负责人: MATSUMOTO Satoru
• 金额: $ 34.36万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13305025/
• 关键词: quntum computating; silicon; spin-free silicon; isotope control; ^<31>P nuclear spin; nuclear magnetic resonance; atomic layer doping; quantum dynamics

In Si-based quantum computer, ^<31>P should be distributed in an array at a distance of about 20 nm in spin-free silicon (spin zero ^<28>Si or ^<30>Si) as a qubit. In the present work, in order to fabricate its basic device structure, we aim to perform the experiments on the epitaxial growth of isotopically controlled silicon layers and the transformation of ^<30>Si to ^<31>P by neutron irradiation. This method for distributing ^<31>P in Si is superior to the ion-implantation technique, which is inherently random to the depth. For this purpose, first, epitaxial growth technique of almost 100% ^<30>Si was developed by the gas source MBE method using enriched ^<30>SiH_4, which was purchased from Kurchatov laboratory, Russia. Thus this spin-free Si epitaxial layer can be available to the base for Si-based quantum computer. Using this technique, we succeeded to fabricate the natural Si/^<30>Si/natural Si (^<28>Si:^<29>Si:^<30>Si=92.2:4.7:3.1) isotope double hetero-structures by supplying alternately normal SiH_4 and enriched ^<30>SiH_4. Then, neutron irradiation was carried out to transform ^<30>Si to ^<31>P at Japan Atomic Energy Research Institute with thermal neutron flux of 1×10^<14> cm^<-2> s^<-1> for 16 h. By the precise secondary ion mass spectroscopy (CAMECA-SIMS) measurement, the formation of ^<31>P from ^<30>Si was confirmed. Its concentration was to be about 5×10^<16> cm^<-3>w, which was almost equal to the theoretically predicted value. If the neutron irradiation is performed to the ^<29>Si/^<30>Si/^<29>Si double hetero-structures, nuclear spin ^<31>P will be distributed in a spin-free silicon (^<31>Si ), which will be used as a basic structure of Si-based quantum computer.

在基于Si的量子计算机中，^<31>P应该作为量子比特在无自旋硅（自旋零^ Si或^ Si）中以大约20 nm的距离分布在阵列中<28><30>。在目前的工作中，为了制造其基本的器件结构，我们的目标是进行实验的同位素控制的硅层的外延生长和通过中子辐照的^<30>Si到^<31>P的转变。这种在Si中分布P的方法<31>比离子注入技术优越上级，离子注入技术本质上对深度是随机的。为此，首先，我们利用从俄罗斯库尔恰托夫实验室购买的<30>富集的^SiH_4气体源分子束外延法，发展了几乎100%^Si的外延生长技术<30>。因此，这种无自旋硅外延层可用于硅基量子计算机的基底。利用该技术，我们成功地制备了天然Si/^<30>Si/天然Si（^<28>Si：^<29>Si：^<30>Si=92.2：4.7：3.1）同位素双异质结构<30>。然后，<30><31>在日本原子能研究所用热中子通量为1×10^<14>cm^<-2>s^<-1>的中子辐照16 h，将^ Si转化为^ P。通过精确二次离子质谱（CAMECA-SIMS）测量，证实<31>了^ Si形成^ P<30>。其浓度约为5×10^<16>cm^<-3>w，这几乎等于理论预测值。如果对^<29>Si/^<30>Si/^<29>Si双异质结构进行中子辐照，核自旋^<31>P将分布在无自旋硅（^<31>Si）中，这将用作Si基量子计算机的基本结构。

项目成果

松本 智: "半導体デバイスの基礎"培風館. 236 (2003)

松本聪：《半导体器件基础》Baifukan 236 (2003)。

Y.Nakabayashi, H.I.Osman, K.Yokota, K.Toyonaga, S.Matsumoto, J.Murota, K.Wada, T.Abe: "Type and charge states of point defects in heavily As-and B-doped silicon"Materials Science in Semiconductor Processing. Vol.6. 15-19 (2003)

Y.Nakabayashi、H.I.Osman、K.Yokota、K.Toyonaga、S.Matsumoto、J.Murota、K.Wada、T.Abe：“重砷和硼掺杂硅中点缺陷的类型和电荷状态”材料

M.Eto: "Current-Induced Entanglement of Nuclear Spins in Quantum Dots"J.Phys.Soc.Jpn. 73. 307-310 (2004)

M.Eto：“量子点中核自旋的电流诱导纠缠”J.Phys.Soc.Jpn。

Y.Jeong: "Effects of various Hydrogenation Processes on Bias-stress-Induced Degradation in in P-channel Poly TFT"Jpn.J.Appl.Phys.. 41. 5046-5064 (2002)

Y.Jeong：“各种氢化过程对 P 沟道多晶硅 TFT 中偏置应力诱导退化的影响”Jpn.J.Appl.Phys.. 41. 5046-5064 (2002)

N.Fijiwara, K.Saito, Y.Nakabayashi, H.I.Osman, S.Matsumoto, Y.Sato: "Effect of Nitrogen segregation on TED and loss of phosphorus in CZ-Si"Nuclear Instruments and Methods in Physics Research. Vol.B186. 313-317 (2002)

N.Fijiwara、K.Saito、Y.Nakabayashi、H.I.Osman、S.Matsumoto、Y.Sato：“氮偏析对 TED 的影响和 CZ-Si 中磷的损失”物理研究中的核仪器和方法。