A gate-controlled bidirectional spin filter using quantum coherence

被引:136
作者
Folk, JA [1 ]
Potok, RM
Marcus, CM
Umansky, V
机构
[1] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA
[2] Weizmann Inst Sci, Braun Ctr Submicron Res, IL-76100 Rehovot, Israel
关键词
D O I
10.1126/science.1078419
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
We demonstrate a quantum coherent electron spin filter by directly measuring the spin polarization of emitted current. The spin filter consists of an open quantum dot in an in-plane magnetic field; the in-plane field gives the two spin directions different Fermi wavelengths resulting in spin-dependent quantum interference of transport through the device. The gate voltage is used to select the preferentially transmitted spin, thus setting the polarity of the filter. This provides a fully electrical method for the creation and detection of spin-polarized currents. Polarizations of emitted current as high as 70% for both spin directions (either aligned or anti-aligned with the external field) are observed.
引用
收藏
页码:679 / 682
页数:4
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