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arXiv · 2208.12800

Unified theory of spin and charge in a ferromagnet

Oleg Tchernyshyov
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Abstract

We derive a unified theory of spin and charge degrees of freedom in a ferromagnet. The spin-transfer torque and spin electromotive force are examined from the coarse-grained perspective of collective coordinates. The resulting equations of motion reflect a balance of conservative, gyroscopic (Berry-phase), and dissipative forces. We then expand the space of collective coordinates by adding the electric charge. The adiabatic spin-transfer torque and spin emf turn out to be a gyroscopic force; their nonadiabatic counterparts are a dissipative force.

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Oleg Tchernyshyov. 2022-08-26. Unified theory of spin and charge in a ferromagnet. https://doi.org/10.1088/1361-648x%2Fac9dd9

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