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Spin-Selective Resonant Charge-Thransfer in Atom-Surface Scattering and Its Application to Observation of Spin Correlation at Surface

原子-表面散射中的自旋选择性共振电荷转移及其在表面自旋相关观测中的应用

基本信息

批准号：
11440105
负责人：
TORIKAI Eriko
金额：
$ 9.02万
依托单位：
Yamanashi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

Spin fluctuation at a surface as well as its perturbation caused by an observation play an important role on a resolution limit of spin electronics with quantium structures. In order ot study the spin correlation at the topmost layer of magnetic surfaces, we have been developing the spin-polarzed atomic scattering method. In elementary scattering processes of spin-polarized atoms at a material surface, it is expected that the probability of the resonant charge transfer reflects spin density of states of the target surface as well as the relative ionization potential of the atom. This enables us to investigate the spin correlation of the top-most layer of the surface and adsorbents on it with a help of the state analysis techniques for scattered atoms developed in this work.In our method, we employ the Cs atomic berm with a nearly perfect spin-polarization in the atomic growun state including both the electronic and nuclear spins. This is achieved by the technique of optical pumping wit … More h circularly polarized laser light. In this work we have optimized the schmes of optical pumping fit for an extended kinetic energy range of Cs beam between 0.1 〜 10 keV. We have developed a novel charge-state analyzer for scattered atoms based on the technique of the spin-selective resonant two-photon ionization spectroscopy.As the basis of further development of this study into spin measurements of nano-structured materials, we have investigated the pseudo-angular momentum of optical near-fields and its applocation to spin polarization via optical pumping of atomic objects near a material surface. As the experimenttal results the wxistence of the locally rotating optical near-field has been demonstrated for the irst time by using a set of near-field light scattering experiments using small dielectric probes and an ultra-high sensitivity polarization analiyzing system with a cooled CCD camera. We have developed a quantum optical theory of near-field optical pumping and investigated the basic properties of spin measurements and manipulation in mesoscopic devices. We have also performed a set of preliminary experimental study on the sample targets of Ni, GaAs/GaAsP/Si with optical spin injection, single crystalline rare-gas thin film, spin cluster, and biological DNA samples. Less

表面自旋涨落以及由观测引起的自旋扰动对量子结构自旋电子学的分辨极限起着重要的作用。为了研究磁性表面顶层的自旋相关，我们发展了自旋极化原子散射方法。在自旋极化原子在材料表面的基元散射过程中，共振电荷转移的几率反映了靶表面的自旋态密度以及原子的相对电离势。这使我们能够研究的最上层的表面和吸附剂的自旋相关的帮助下，散射原子的状态分析技术，在我们的工作中，我们采用了Cs原子台阶具有近乎完美的自旋极化的原子生长态，包括电子和核自旋。这是通过光抽运技术实现的， ...更多信息 h圆偏振激光。在本工作中，我们优化了适用于0.1 ~ 10 keV扩展动能范围的Cs束光抽运方案。基于自旋选择共振双光子电离光谱技术，我们研制了一种新型的散射原子电荷态分析仪，并在此基础上研究了近场光学赝角动量及其在材料表面原子自旋极化中的应用，为进一步开展纳米材料自旋测量研究奠定了基础。作为实验结果，我们首次用一套小介质探针的近场光散射实验和一套超高灵敏度的冷CCD偏振分析系统证实了局部旋转光学近场的存在。我们发展了近场光抽运的量子光学理论，研究了介观器件中自旋测量和操纵的基本性质。我们还对Ni、GaAs/GaAsP/Si光自旋注入样品靶、单晶稀有气体薄膜、自旋团簇和生物DNA样品进行了初步的实验研究。少