Dynamic effects in current-access dual conductor perforated sheet magnetic bubble logic gates

A magnetic bubble logic gate relying on bubble-bubble repulsion is fabricated in an 8 μm period dual conductor perforated sheet technology with 2 μm minimum line width. Experimental results for a single input bubble are given in detail. At zero applied in-plane field, the effects of gyrotropic forces are consistent with the observed gate behavior of bubbles turning left or right depending on bias field direction. The gyrotropic model cannot, however, describe gate behavior at in-plane fields above 220 Oe: Reversal of either the in-plane or bias field changes the margins but reversal of both fields yields similar margins. This effect is maximum when the in-plane field is perpendicular to the propagation direction. This behavior is inconsistent with the abrupt change from deflecting to nondeflecting bubbles observed at a 220 Oe in-plane field on this sample, interpreted as a change from a to the state. These effects may be due to anisotropic magnetostriction or crystalline anisotropy above in-plane fields of 220 Oe, and also to gyrotropic forces at lower in-plane fields.