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Generator of Up and Down Bubble Domains

IP.com Disclosure Number: IPCOM000083284D
Original Publication Date: 1975-Apr-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Chaudhari, P: AUTHOR [+3]

Abstract

In the bubble lattice file concept it is essential to be able to create distinguishable kinds of bubbles, e.g., left-handed or right-handed, hard or soft. What is proposed, is a method for producing up and down bubbles in the same bubble domain sample and their use to represent 1's and 0's in the bubble lattice file.

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Generator of Up and Down Bubble Domains

In the bubble lattice file concept it is essential to be able to create distinguishable kinds of bubbles, e.g., left-handed or right-handed, hard or soft. What is proposed, is a method for producing up and down bubbles in the same bubble domain sample and their use to represent 1's and 0's in the bubble lattice file.

Up and down bubbles are represented schematically in Fig. 1. An isolated up bubble can only exist as an isolated entity as a doughnut, as shown in Fig. 2. The up bubble or doughnut will behave in much the same way as a down bubble in a low-bias field, since its external wall will dominate its propagation behavior. In an applied positive bias (up), the "hole" of the doughnut will expand while down domains will shrink. This difference in behavior can be used in detection, since both the sign and the magnitude of the signal are different for an up and a down bubble.

In zero bias, bubbles and doughnuts pack together in a lattice in much the same way as bubbles. A dense bubble lattice, of either up or down bubbles, can be nucleated by the application of appropriate in-plane and perpendicular magnetic fields. The sample is saturated in-plane. A small perpendicular component having the same sign as the reference bias field (e.g., up), will nucleate domains having the opposite sign (e.g., down).

For the bubble lattice file application, it would be desirable to generate bubbles or doughnuts at will. The lattice is first prepared as a dense pack of bubbles. The bubbles are propagated row-by-row through an e...