Jedema F J, Heersche H B, Filip A T, Baselmans J J A, van Wees B J
Department of Applied Physics and Materials Science Center, University of Groningen, The Netherlands.
Nature. 2002 Apr 18;416(6882):713-6. doi: 10.1038/416713a.
To study and control the behaviour of the spins of electrons that are moving through a metal or semiconductor is an outstanding challenge in the field of 'spintronics', where possibilities for new electronic applications based on the spin degree of freedom are currently being explored. Recently, electrical control of spin coherence and coherent spin precession during transport was studied by optical techniques in semiconductors. Here we report controlled spin precession of electrically injected and detected electrons in a diffusive metallic conductor, using tunnel barriers in combination with metallic ferromagnetic electrodes as spin injector and detector. The output voltage of our device is sensitive to the spin degree of freedom only, and its sign can be switched from positive to negative, depending on the relative magnetization of the ferromagnetic electrodes. We show that the spin direction can be controlled by inducing a coherent spin precession caused by an applied perpendicular magnetic field. By inducing an average precession angle of 180 degrees, we are able to reverse the sign of the output voltage.
在“自旋电子学”领域，研究并控制在金属或半导体中移动的电子自旋行为是一项重大挑战，目前该领域正在探索基于自旋自由度的新型电子应用的可能性。最近，通过光学技术在半导体中研究了输运过程中自旋相干性和相干自旋进动的电控制。在此，我们报告了在扩散金属导体中，利用隧道势垒结合金属铁磁电极作为自旋注入器和探测器，实现了对电注入和检测电子的可控自旋进动。我们器件的输出电压仅对自旋自由度敏感，并且其符号可根据铁磁电极的相对磁化强度从正变为负。我们表明，通过施加垂直磁场诱导相干自旋进动，可以控制自旋方向。通过诱导180度的平均进动角，我们能够反转输出电压的符号。
