A Study on Spin-Polarized Tunneling Phenomena and its Applications.

我们研究了量子隧穿现象，这是开发SP-STM的基础研究。我们的SP-STM可以在不影响尖端的情况下观察表面的微磁状态。(1) 1992年利用STM成功地观测到了GaAs样品与Ni针尖之间的自旋极化隧道电流。(2)开发了UHV-STM系统，并明确了隧道电流取决于入射光的极性和Ni尖端的磁化强度。观察到光伏效应并测量了STS，从而了解了这些材料的能带结构和自旋极化。(3)我们还在开发量子阱结构，这是一种利用FIB和莫特自旋分析仪对尖端进行处理的技术。

We have studied the quantum tunneling phenomena that are the basic research of developing SP-STM.Our SP-STM can observe micro magnetic states of surfaces without an affection of the tip.(1) We succeeded in observing the spin polarized tunneling current between GaAs sample and Ni tip by STM in 1992.(2) The UHV-STM system has been developed and it becomes clear that the tunneling current depends on the polarity of the incident light to the GaAs sample and the magnetization of the Ni tip. A photovoltaic effect was observed and STS was measured, so we can understand the energy band structure and spin polarization of these materials.(3) We are also developing a quantum well structure, a technology of processing to the tip by FIB and Mott spin analyzer.