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

表面自旋涨落及其观测引起的微扰对量子结构自旋电子学的分辨极限起着重要的作用。为了研究磁表面最顶层的自旋关联，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本散射过程中，共振电荷转移的几率不仅反映了目标表面的自旋密度，而且反映了原子的相对电离势。这使得我们能够借助这项工作中开发的散射原子的状态分析技术来研究表面最顶层和吸附在其上的自旋相关性。在我们的方法中，我们使用了原子生长态中具有近乎完美的自旋极化的Cs原子护堤，包括电子自旋和原子核自旋。这是通过利用…的光泵浦技术来实现的更多的h圆偏振激光。在这项工作中，我们优化了适合Cs束动能范围在0.1~10keV范围内的光泵浦方案。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状态分析器。作为进一步发展这一研究到纳米材料自旋测量的基础，我们研究了光学近场的赝角动量及其在材料表面附近原子的光泵浦下对自旋极化的应用。作为实验结果，利用一套小型介质探头的近场光散射实验和一套带冷却的CCD相机的超高灵敏度偏振分析系统，首次证明了局部旋转光学近场的存在。我们发展了近场光泵浦的量子光学理论，并研究了介观器件中自旋测量和操纵的基本性质。我们还用光学自旋注入、单晶稀有气体薄膜、自旋团簇和生物DNA样品对Ni、GaAs/GaAsP/Si样品靶进行了初步实验研究。较少

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