Improved propagation, stretching and annihilation of magnetic bubbles in current-access devices

Abstract

New functional elements have been tested for 16 μm-period current-access circuits in single and double mask structures. Improved propagate patterns exhibit 15% operating margins at 1 MHz frequency and 20 mA current. Heat dissipation drops to 0.3 mW per conductor period. In conventional CaGe-garnet films it has been possible to increase the maximum frequency to 1.9 MHz at 60 mA. In the first orthorhombic films to be processed, 4 MHz has been reached already at 20 mA current. High-frequency current-access stretching of bubbles prior to detection is discussed. Operating margins of 10% are obtained up to 700 kHz in a pattern that stretches bubbles normal to their propagation direction. High-frequency writing is obtained by combining a number of field-access generators with an annihilator in the conductor track. A compact current-field-access swap gate allows the closest possible packing of the field-access minor loops. These elements have not yet been combined for the same conductor structure. In principle, however, the functions required for a field and current-access major-minor loop chip are now available.