Abstract: Magnetic domains with defined wall topologies are controllably generated from a domain having known characteristics. A "mother" bubble domain of a known wall state is generated by nucleation. The mother domain is stretched and split in the presence of a magnetic field directed across the separation area. A pair of Bloch lines is generated in every splitting process. The assignment of the lines to either one of the two resulting domains depending upon the wall state of its mother domain and the direction of the directed magnetic field. Instead of the directed magnetic field, velocity inducing forces can be applied to the elongated domain. The effect desired is to incline the wall magnetization in the elongated section of the domain. Controlled resplitting of domains having Bloch lines increases the number of Bloch lines in one domain to generate any predesignated wall state. The multiplicity of states which can be controllably generated anticipates their utilization beyond binary bit coding.

Abstract: A bubble lattice structure is disclosed containing a barrier positioned between at least two adjacent rows of bubble domains and/or stripe domains. More than one barrier may be utilized to retain integrity of the lattice. The bubble lattice structure containing barriers has a number of advantages or improved operating characteristics such as better control in maintaining the relative position of the bubble domains in the lattice columns adjacent the column of bubbles being accessed, closer control of the number of rows of bubbles in a given area, and a reduction of the distortion of the lattice during lateral translation.

Abstract: Stationary patterns of magnetic domains in a film layer of magnetically hard material define local field gradients for movement control of single-wall domains located in a contiguous sheet of magnetic "bubble" material. Suitable patterns of uniformly magnetized regions are established in the hard-magnetic film to provide the control pattern. A second garnet film of suitable composition, for instance, may be grown epitaxially on the bubble medium to provide the hard magnetic control film. Bubble domain confinement and propagation patterns are established in the hard-magnetic film by conventional recording methods or the desired pattern can be generated by projection or scanning the pattern with a light beam or an electron beam, or by thermomagnetic transfer from a master pattern.

Abstract: A closed loop bubble lattice system and a method for stabilizing the same is disclosed. The closed loop bubble lattice system contains at least one portion being curved wherein the lattice parameter increases with the radius. In a preferred embodiment a radially varying bias field is associated with the curved portion in a manner to provide an equilibrium lattice constant at a bubble domain position which is substantially the same as the lattice parameter for that position. A method of reducing the stress in the curved portion of the bubble domain lattice system to provide stabilization therefor involves the step of varying one or more of the parameters which affect the equilibrium lattice constant.

Abstract: A wall topology storage system wherein information in the form of data bits is stored as polarity reversals in magnetic domain walls separating adjacent magnetic domains. A plurality of bits is stored in each wall as a plurality of reversals, resulting in greater storage capacity than when using the adjacent domain itself.