Swap gate for ion-implanted contiguous-disk bubble devices

Abstract

A swap gate for ion-implanted contiguous disk bubble devices using folded minor loops is disclosed. The bubble device has a major loop, a folded minor loop and a swap element positioned between the major loop and the folded end of the minor loop. The swap element has a first portion for interchanging bubbles with the major loop, a second portion for receiving bubbles from a first region of the folded end of the minor loop, and a third portion for transferring bubbles from the first portion to a second region of the folded end of the minor loop. The folded end of the minor loop also has a third region positioned between the first and second regions to form two bubble storage locations. The bubble device has a conductor associated with the major loop and the first portion of the swap element to form a first transfer gate. The device also includes a second conductor associated with the folded minor loop and the second portion of the swap element to form a second transfer gate. The third portion of the swap element combines with the folded minor loop to form a merge element. In a preferred embodiment, the device has a quadruple period major loop which transfers a block of data into a single bit position on each of the minor loops.