Browse Prior Art Database

Dynamic Detection of Information in Magnetic Bubble Domain Walls

IP.com Disclosure Number: IPCOM000080200D
Original Publication Date: 1973-Nov-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 3 page(s) / 45K

Publishing Venue

IBM

Related People

Argyle, BE: AUTHOR [+3]

Abstract

A number of ways to distinguish two types of bubbles, those with and without vertical Bloch lines, is suggested which is based on differences in their dynamic behavior.

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Dynamic Detection of Information in Magnetic Bubble Domain Walls

A number of ways to distinguish two types of bubbles, those with and without vertical Bloch lines, is suggested which is based on differences in their dynamic behavior.

The first method is described in reference to Fig. 1 which is a block diagram of a system of conventional circuit elements, for propagating and sensing a train of information bubbles containing both Bloch line bubbles and normal bubbles. For a typical material, a 60 Oe magnetic field pulse applied normal to the material will collapse a normal bubble for pulse widths of the order of 0.2 microseconds, whereas a Bloch line bubble takes of the order of 1 microsecond or more to collapse. Thus, 60 Oe pulses of widths greater than 0.2 and less than 1 microsecond can distinguish between these types of bubbles, by collapsing only the normal bubbles.

Referring to Fig. 1, bubble propagation takes place by conventional permalloy overlays and rotating magnetic fields in the plane of the material. Block 10 provides a means of collapsing normal bubbles, such as a small current loop connected to a pulse generator. Unit 12 is a standard sense circuit, such as magnetoresistive sensor, which detects the presence or absence of a bubble. If no bubble is present, this indicates that a normal bubble was collapsed by collapser 10. This provides destructive readout. If nondestructive readout is desired, a normal bubble generator 14 can regenerate the normal bubble. The chain of information is thus restored to its normal condition and propagation carries the train to some other area for storage or further processing. The main feature differentiating the two types of bubbles in the dynamic process is the difference in wall mobility.

Another method which implements this principle is a "bubble gun" in which bubbles are translated in a gradient field. The bubbles without Bloch lines translate furth...