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Single Phase Shift Register using Magnetostatically Coupled Bubble Domains

IP.com Disclosure Number: IPCOM000076240D
Original Publication Date: 1972-Feb-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Chang, H: AUTHOR

Abstract

This shift register uses the biaxial property of orthoferrites when maintained below their transition temperature. Three quiescent stable states are available in this device in which a pair of magnetic bubble domains, oppositely magnetized and magnetostatically coupled to one other, constitute a memory cell. In the shift register environment, the presence or absence of a bubble domain pair represents a 1 or a 0.

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Single Phase Shift Register using Magnetostatically Coupled Bubble Domains

This shift register uses the biaxial property of orthoferrites when maintained below their transition temperature. Three quiescent stable states are available in this device in which a pair of magnetic bubble domains, oppositely magnetized and magnetostatically coupled to one other, constitute a memory cell. In the shift register environment, the presence or absence of a bubble domain pair represents a 1 or a 0.

Bubble domain devices utilizing bubble pairs offer very high-storage density. In contrast to normal bubble domain devices, where the domains are spaced about four times their diameter in order to avoid magnetostatic interaction, magnetostatic interaction is reduced when bubble domain pairs are utilized, so that memory cells can be placed adjacent to each other.

Fig. A shows a memory cell comprising bubble domain a and bubble domain b, which are magnetostatically coupled. The magnetization of each bubble domain is opposite to the other.

Also shown in Fig. A is a figure eight winding for propagation of the bubble domains. This winding is comprised of conductors 1 which are arranged so that the magnetic field normal to the loop winding changes sign from one loop to the next. As the current direction is reversed, the field direction in each loop also is reversed. The triangular shaped wedges 2 are formed of permalloy and guide the bubble domain pairs to move in a particular direction,...