Valley Spin Polarization by Using the Etraordinary Rashba Effect on Silicon

The formation of 100% spin polarized valleys were observed for a Si(111) surface with slightly more than 1ML of Tl on top. The present system opens a new avenue towards the realization of silicon spintronic devices with high efficiency.

K. Sakamoto et al.,   Nature Communications, 2073, DOI: 10 1038/ncomms3073(2013)

The addition of the valley degree of freedom to a two-dimensional spin-polarized electronic system provides the opportunity to multiply the functionality of next-generation devices. So far, however, such devices have not been realized due to the difficulty to polarize the valleys, which is an indispensable step to activate this degree of freedom. Here we show the formation of 100% spin-polarized valleys by a simple and easy way using the Rashba effect on a system with C3 symmetry. This polarization, which is much higher than those in ordinary Rashba systems, results in the valleys acting as filters that can suppress the backscattering of spin-charge. The present system is formed on a silicon substrate, and therefore opens a new avenue towards the realization of silicon spintronic devices with high efficiency.

 

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Nature communications 2073 (2013)
Last Updated on Monday, 04 April 2016 17:25