Schütz Florian, Kollar Marcus, Kopietz Peter
Institut für Theoretische Physik, Universität Frankfurt, Robert-Mayer-Strasse 8, 60054 Frankfurt, Germany.
Phys Rev Lett. 2003 Jul 4;91(1):017205. doi: 10.1103/PhysRevLett.91.017205. Epub 2003 Jul 3.
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 gmicro(B)(T/ variant Planck's over 2pi )exp([-2pi(gmicro(B)B/delta)(1/2)], as obtained from leading-order spin-wave theory. Here g is the gyromagnetic factor, micro(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.
我们表明，在低温T下，具有大小为B的非均匀径向磁场会在介观铁磁海森堡环周围产生持续的磁化电流。在最佳条件下，根据领先阶自旋波理论，这种自旋电流可以大到gμ(B)(T/（2π约化普朗克常数）)exp([-2π(gμ(B)B/δ)^(1/2)]。这里g是旋磁因子，μ(B)是玻尔磁子，δ是基态与第一自旋波激发之间的能隙。磁化电流赋予环一个电偶极矩。
