Triangular propagation patterns for contiguous-disk magnetic bubble devices

Triangular propagation patterns1 are proposed for contiguous-disk magnetic bubble devices in ion-implanted garnet films with tridirectional crystalline inplane anisotropy. These patterns offer superior results in bias field margins (53 Oe or 15%), and allow decreases in inplane drive field as well as high frequency operations (up to 700 kHz). The underlying theory for designing the propagation pattern based on the three-vetex critical curves and micromagnetic structures is discussed. A simple design rule for pattern geometry and orientation to optimize the bias margin and minimum drive is presented.