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Multiple Layer Bubble Lattice Files

IP.com Disclosure Number: IPCOM000087220D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 43K

Publishing Venue

IBM

Related People

Beausoleil, WF: AUTHOR [+2]

Abstract

Bubble domain coding in a magnetic bubble lattice file is achieved by using bubble domains in separate magnetic layers. This provides improved stability and devices in which information representation is not dependent on wall structure. In this manner, the device coding is less vulnerable to hard/soft bubble complications.

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Multiple Layer Bubble Lattice Files

Bubble domain coding in a magnetic bubble lattice file is achieved by using bubble domains in separate magnetic layers. This provides improved stability and devices in which information representation is not dependent on wall structure. In this manner, the device coding is less vulnerable to hard/soft bubble complications.

In Fig. 1, paired bubble domains in two storage films 10 and 12 represent I/O, and a third magnetic film 14 sustains much larger bubble domains to convey a cluster of many small bubble pairs in the films 10 and 12. Magnetic domains in the two storage films have opposite magnetization directions. When their arrows are away from each other, the pair represents a 1, while the pair represents a 0 when their arrows are toward one another. In this figure, the boundaries of a magnetic bubble are indicated by the solid lines, while the dashed lines indicate regions of the bubble domain films whose magnetization direction is being considered.

A pair of magnetic domains by themselves would align their magnetizations in the same direction. However, in the environment of two films, a closely spaced lattice of bubble pairs helps reduce the magnetostatic energy as a whole, and the lattice should have a more stable magnetic field range. The two films sustaining a lattice of bubble pairs will still have a net magnetization, although it is greatly reduced. A small bias field is needed to sustain the small magnetization.

Many individual bubble pairs can be grouped into a bubble cluster. The bubble cluster can be considered as a single bubble in conventional bubble devices. The magnetization surrounding the bubble cluster is opposite to the net magnetization of the bubble cluster. A domain wall will define the boundary of the bubble cluster and confine the individual bubble pairs within the boundary. The bubble cluster can be propagated by conventional means, such as current loops or permalloy overlays. However, since the bubble cluster can be packed into a dense array, a third magnetic film 14 can be used to provide a...