Time-dependent domain wall nucleation probability in field-coupled nanomagnets with perpendicular anisotropy

In this paper, the domain wall (DW) nucleation time and the DW nucleation probability of field-coupled magnets with perpendicular magnetic anisotropy are measured by experiment. A well-established Arrhenius model based on thermally activated magnetization reversal is applied to describe the time-dependent DW nucleation probability. Magneto-optical microscopy(MOKE) is used in the experiments to determine the DW nucleation time and the DW nucleation probability in a pNML inverter structure. The DW propagation speed is measured in order to calculate the required DW propagation time for entire magnetization reversal of pNML logic gates. Experimental results are compared to the derived model. Our results show that the interaction in pNML logic gates plays a significant role for the time-dependent DW nucleation probability and therefore for the reliability of field-coupled circuits.