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Conservation of spin current

Jian Wang·Baigeng Wang·Wei Ren·Hong Guo
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Abstract

The conventional definition of spin-current, namely spin density multiplied by the group velocity, is not a conserved quantity due to possible spin rotations caused by spin-orbit (SO) interaction. However, in a model with spin-spin interactions, rotation of a spin causes a dynamic response of surrounding spins that opposes the rotation. Such a many-body effect restores the spin-current conservation. Here we prove that the non-conservation problem of spin-current can be resolved if a self-consistent spin-spin interaction is included in the analysis. We further derive a spin-conductance formula which partitions spin-current into different leads of a multi-lead conductor.

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Jian Wang, Baigeng Wang, Wei Ren, Hong Guo. 2006-02-24. Conservation of spin current. https://arxiv.org/abs/cond-mat/0507159

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