title: Persistent spin currents in mesoscopic Heisenberg rings.
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 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.
authors.affiliation: Institut für Theoretische Physik, Universität Frankfurt, Robert-Mayer-Strasse 8, 60054 Frankfurt, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Schütz
authors.forename: Marcus
authors.initials: M
authors.lastname: Kollar
authors.forename: Peter
authors.initials: P
authors.lastname: Kopietz