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Bubble Domain Manipulation Using Induced Magnetic Fields

IP.com Disclosure Number: IPCOM000087197D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 60K

Publishing Venue

IBM

Related People

Chaudhari, P: AUTHOR [+3]

Abstract

Various bubble domain devices are provided using a current flow through an electrical conductor capable of supporting magnetic bubble domains. For example, such materials include GdCo(5) and amorphous magnetic bubble domain materials.

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Bubble Domain Manipulation Using Induced Magnetic Fields

Various bubble domain devices are provided using a current flow through an electrical conductor capable of supporting magnetic bubble domains. For example, such materials include GdCo(5) and amorphous magnetic bubble domain materials.

In Fig. 1, a suitable electrically conductive bubble domain material is located on a substrate. A current I flowing through the bubble domain material will induce a magnetic field in the material having vertical components of opposite signs at the opposing edges of the material stripe, as indicated by the plus and minus signs. In order to propagate bubble domains along the length of the stripe, it is necessary to create a magnetic field gradient in the intended direction of movement. This gradient is obtained in two ways, as is illustrated in Figs. 2-4. In the first way, the current density along the length of the material stripe is varied by changing the cross-sectional area of the stripe (Figs. 2 and 3), while in the second way, the field gradient is produced by a proper overlay pattern on the bubble domain material stripe (Fig. 4).

In Fig. 2, the stripe has an asymmetric sawtooth cut along one edge, which is used to provide regions of high pole strength for movement of the bubble domains. The constricted portions of the stripe are regions of high negative pole strength when the current I is in the direction indicated by the arrow. These constricted portions are very attractive to positive bubble domains. This is indicated by the bubble domain which moves to the position shown by the dashed line close to a position of high negative field strength. When the current flow is reversed (Fig. 3), the constricted regions of the sawtooth edge become regions of high positive pole strength. This repels the bubble domain as illustrated by the movement of the domain to the new position indicated by the dashed outline. The asymmetric sawtooth cut of the stripe insures that the field gradient is steepest in the desired direction of propagation.

Fig. 4 shows the use of an overlay on the stripe to produce the field gradient. A suitable overlay is comprised...