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Persistent spin currents in mesoscopic Heisenberg rings

Florian Schuetz·Marcus Kollar·Peter Kopietz
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Abstract

We show that at low temperatures T an inhomogeneous radial magnetic field with magnitude B gives rise to a persistent magnetization current around a mesoscopic ferromagnetic Heisenberg ring. Under optimal conditions this spin current can be as large as g mu_B (T / hbar) exp [ - 2 pi (g mu_B B / Delta )^1/2 ], as obtained from leading-order spin-wave theory. Here g is the gyromagnetic factor, mu_B is the Bohr magneton, and Delta is the energy gap between the ground state and the first spin-wave excitation. The magnetization current endows the ring with an electric dipole moment.

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Florian Schuetz, Marcus Kollar, Peter Kopietz. 2003-07-07. Persistent spin currents in mesoscopic Heisenberg rings. https://doi.org/10.1103/physrevlett.91.017205

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