Spin-Orbit and Magnetic Scattering and Non-Equilibrium Properties by Weak Localization

利用金属薄膜中电子的微弱局域化，观察了电子与杂质原子的自旋-轨道相互作用和磁性电子-杂质原子相互作用引起的电子散射。作为外加磁场的函数测量的输运数据可以被解释为产生关于杂质原子的电子结构的信息。对S和p杂质的早期研究正在扩大和扩展，以包括d杂质。另外一个子项目将研究高电流密度影响下的薄膜。这对应于电子温度远高于声子温度的稳定非平衡态。这样的测量提供了有关电子-声子系统、电子-声子相互作用以及薄膜和衬底之间的卡皮扎电阻的信息。由于量子效应，金属中的电子既表现出粒子性质，又表现出波性质。在低温下，电子波在很长的距离内是相干的，并影响金属的性质。具体地说，由于电子波可能相互干扰，因此改变了诸如电阻之类的传输特性。外加磁场改变了电子波的相位，改变了干涉。因此，电阻取决于磁场。(由于历史原因，这种现象被称为弱本地化)。对磁阻的仔细分析揭示了电子作为时间函数的命运的详细信息。例如，我们可以在很短的皮秒(百万分之一秒)的时间尺度上确定电子自旋作为时间的函数。当电子遇到杂质时，就会发生这样的旋转，称为自旋-轨道散射。人们正在研究各种杂质原子(铜、锌、金、锡等)的这种散射。在宿主金属镁中。这项研究提供了有关金属和合金的磁性和电学性质的重要信息，并将有助于开发具有有用性能的新材料，特别是在低温下。

Weak localization of electrons in thin metal films is used to observe electron scattering from impurity atoms arising from spin- orbit and magnetic electron-impurity atom interactions. Transport data measured as a function of an applied magnetic field can be interpreted to yield information about the electronic structure of the impurity atoms. Earlier research on s and p impurities is being expended and extended to include d impurities. An additional subproject will investigate thin films under the influence of a high current density. This corresponds to a steady non-equilibrium state with the electron temperature considerably above the phonon temperature. Such measurements yield information about the electron-phonon system, the electron-phonon interaction and the Kapitza resistance between film and the substrate. %%% Because of quantum effects, electrons in metals display both particle and wave properties. At low temperatures, the electron waves are coherent over extended distances and influence the properties of the metal. In particular, the transport properties such as the resistance are modified because the electron waves can interfere with each other. An external magnetic field alters the phase of the electron waves and modifies the interference. As a consequence the resistance depends on the magnetic field. (For historical reasons, this phenomena is called weak localization). A careful analysis of the magneto-resistance reveals detailed information about the fate of the electrons as a function of time. For example, we can determine the rotation of the electron spin as a function of time on the very short time scale of pico-seconds (one millionth of a millionth of a second). Such a rotation occurs when the electron encounters impurities and is called spin-orbit scattering. This scattering is being studied for various impurity atoms (copper, zinc, gold, tin, etc.) in host magnesium metal. The research provides important information about the magnetic and electronic properties of metals and alloys and will aid in the development of new materials with useful properties, particularly at low temperatures.