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Symmetric Chevron Patterns for Field Access of Bubble Lattices

IP.com Disclosure Number: IPCOM000088168D
Original Publication Date: 1977-Apr-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 4 page(s) / 91K

Publishing Venue

IBM

Related People

Chang, H: AUTHOR [+2]

Abstract

Symmetric chevron elements arranged in an array can be used to move bubble domain lattices in response to the reorientation of a magnetic field in the plane of the bubble material. These symmetric chevron elements will move the lattice bubble domains bi-directionally depending upon the sense of rotation of the in-plane magnetic field. Further, arrays of symmetric chevron elements can be provided which will move multiple rows and columns of bubble domains in the lattice per chevron row and column. This provides drive arrays of chevron elements that are easily fabricated without stringent lithography.

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Symmetric Chevron Patterns for Field Access of Bubble Lattices

Symmetric chevron elements arranged in an array can be used to move bubble domain lattices in response to the reorientation of a magnetic field in the plane of the bubble material. These symmetric chevron elements will move the lattice bubble domains bi-directionally depending upon the sense of rotation of the in-plane magnetic field. Further, arrays of symmetric chevron elements can be provided which will move multiple rows and columns of bubble domains in the lattice per chevron row and column. This provides drive arrays of chevron elements that are easily fabricated without stringent lithography.

The symmetric chevron elements have bar lengths which are equal to one another, and different elements can be provided by changing the length of the bars and the angle at the apex of these bars. Figs. 1A, 1B and 1C illustrate three chevron elements of differing geometry. In these figures, the coordinate points (0,0) (1,0), etc., represent lattice points. Thus, the figures show the chevron elements and their positioning in the lattice.

A lattice of bubble domains B and the associated chevron pattern array is shown in Fig. 2. Figs. 3A, 3B, 3C and 3D illustrate the movement of four bubble domains B1, B2, B3 and B4 in response to the reorientation of the magnetic field
H.

In Fig. 2, the permalloy chevron elements have a periodic structure conforming to the closely packed hexagonal arrangement of bubbles in the lattice. The periodicity of the permalloy elements is larger than that for the bubble lattice. The column and row directions of the tilted array of permalloy chevrons conforms, respectively, to the 60 degree and 0 degree axes of the bubble lattice. Each chevron element embraces the area of four bubble domains.

Referring to Figs. 3A-3D, as the planar field H rotates, bubble B1 is actively driven during field phases 1, 2 and 3, moving from the right-hand tip of one chevron across the gap to the left tip of another chevron. During phase 4, it is pushed off the chevron by a repulsive pole, still maintaining the same direction of motion.

For bubble B3, during phases 1, 2 and 3, it is indirectly dri...