Tunable Spin Polarization in Bismuth Ultrathin Film on Si(111)
Tunable Spin Polarization in Bismuth Ultrathin Film on Si(111)
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DOI：
10.1021/nl2035018
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发表时间：
2012-04-01
期刊：
影响因子：
10.8
通讯作者：
Takahashi, Takashi
中科院分区：
文献类型：
--
作者：
Takayama, Akari;Sato, Takafumi;Takahashi, Takashi
我们在不同膜厚d的Si(111)衬底上对铋超薄膜进行了自旋和角度分辨光电子能谱研究，发现在布里渊区边界附近的自旋分裂Rashba表面态的自旋极化在d=40bl(双层)时很高(0.7)，随着d的减小而逐渐减小，在d=8bl时几乎消失。这一发现为产生自旋极化可调的电子提供了一种新的方法。
We performed a spin- and angle-resolved photoemission spectroscopy of bismuth ultrathin film on Si(111) with various film thickness d. We found that the spin polarization of spin-split Rashba surface states near the Brillouin-zone boundary, which is high (0.7) at d = 40 BL (bilayers), is gradually reduced on decreasing d and almost vanishes at d = 8 BL. This finding provides a novel method to generate spin-polarized electrons with tunable spin-polarization.