Stability of magnetic nanowires against spin-polarized current

Stability of ground magnetization state of a thin magnetic nanowire against longitudinal spin-polarized current is studied theoretically with dipole-dipole interaction taken into account. The critical current, minimum current at which the instability of the ground state develops, is determined. Dependence of the critical current on size and form of the transversal wire cross-section is clarified. Theoretical predictions are confirmed by numerical micromagnetic simulations.