Application of all-optical nuclear magnetic resonance to quantum computing

全光核磁共振在量子计算中的应用

基本信息

批准号：
14076203
负责人：
OHNO Yuzo
金额：
$ 12.54万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14076203/
关键词：
quantum computer nuclear spin precession quantum well Gallium Arsenide Faraday rotation

项目摘要

The purpose of the research is to elucidate the dynamics of interaction between electron and nuclear spins in semiconductor quantum structures, and establish fundamental technology for solid state quantum computation in which nuclear spin is utilized as a qubit The achievements of the research are summarized as :1. We demonstrated that the hyperfine interaction and dynamic nuclear polarization can be controlled by changing the background electron density with gate electric field in a gated n-GaAs/A1GaAs (110) quantum well. We showed that the experimental observation can be explained by metal-insulator transition, on which the hyperfine interaction depends sensitively.2. We demonstrated detection nuclear spin coherence in semiconductor quantum wells by a time-resolved Kerr rotation (TRKR) technique combined with manipulation by pulse rf NMR. The temporal nuclear polarization after the irradiation of a single-pulsed resonant rf magnetic field was observed by measuring the change of the Kerr rotation at a fixed time delay between pump and probe pulses. We traced the Rabi oscillation as a function of the rf pulse width. We also employed a spin-echo technique to evaluate the intrinsic coherence time, which reveals the dependence on the orientation of the magnetic field with respect to the crystalline axis as expected by the nearest neighbor dipole-dipole interaction.

研究目的是阐明半导体量子结构中电子与核自旋相互作用的动力学，建立以核自旋为量子比特的固态量子计算基础技术。研究成果概括为：1 。我们证明了可以通过改变门控 n-GaAs/AlGaAs (110) 量子阱中的栅极电场背景电子密度来控制超精细相互作用和动态核极化。我们证明实验观察可以用金属-绝缘体转变来解释，超精细相互作用敏感地依赖于金属-绝缘体转变。2．我们展示了通过时间分辨克尔旋转（TRKR）技术与脉冲射频核磁共振操作相结合来检测半导体量子阱中的核自旋相干性。通过测量泵浦脉冲和探测脉冲之间固定时间延迟下克尔旋转的变化，观察单脉冲共振射频磁场照射后的时间核极化。我们追踪了拉比振荡作为射频脉冲宽度的函数。我们还采用自旋回波技术来评估固有相干时间，这揭示了磁场相对于晶轴的方向的依赖性，正如最近邻偶极子-偶极子相互作用所预期的那样。