Current driven domain wall creation in ferromagnetic nano-wires

We predict the electrical generation and injection of domain walls into a ferromagnetic nano-wire without the need of an assisting magnetic field. Our theory shows that above a critical current $j_c$ domain walls are injected into the nano-wire with a period $T\sim (j-j_c{)}^{-1\mathrm{/}2}$. In a uniaxial anisotropy geometry this process does not require Dzyaloshinskii-Moria or dipole-dipole interaction and can be done in a simple exchange ferromagnet. We also show that this process and the period exponents are universal and do not depend on the peculiarities of the microscopic Hamiltonian.