Major line operation in vertical Bloch line memory

Abstract

The operation of a major line in a vertical Bloch line memory using a partial garnet grooving architecture was studied experimentally and numerically. The major line was fabricated on a 5-μm bubble garnet using three conductor layers and a 10% garnet grooving. The major line contains a bubble generator, a bubble propagation track, a bubble expander for bubble detection, and a bubble annihilator. The minimum current for bubble generation was 350 mA, at 50 ns pulse width. The bubble propagation track was a typical dual conductor design with a 5-μm-wide conductor and a 20-μm circuit period. The minimum drive current was 5 and 10 mA at an operating frequency of 250 and 500 kHz, respectively. The bias field margin was from 84 to 100 Oe. The bubble expander was a modification of the propagation track. The meandering conductor and the groove width were gradually increased to stretch the bubble into a stripe. The bias field margin was from 82 to 84 Oe. The numerical model includes the effect of the garnet grooving, and the simulation results agree with the experimental data.