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【答案】应助回帖
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柠檬树: 金币+30, 翻译EPI+1, ★★★★★最佳答案, 给你多的吧 如果版主处理了 我再给你那个帖子的 谢谢哈 2013-03-15 09:16:30
1) In such circumstances, the conductance is quantized with the unit 2e2/h for the non-magnetic materials. However, the unit for the magnetic materials should be e2/h due to lifting of the spin degeneracy by the exchange interaction. In recent study on the Ni ballistic nanocontacts, it was found that the magnetoresistance signal depends on whether the current and the magnetic field are parallel or perpendicular. Bu this kind of behavior was interpreted as the traditional signature of AMR.
2) The ballistic conductance is given by the equation G=Ne2/h, where the number N is much strongly influenced by the spin-orbit interaction in nano-constrained geometries than that in a bulk material. The coupling between self-spins and the orbital angular momentums results in anisotropic effects because it causes changes of the projection of the former (self-spin) with the magnetization direction. Therefore, the ballistic conductance can be tuned by fashioning (changing) the number of bands on the Fermi surface via. adjudgement of the magnetization direction. |
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