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Electrical Sensing of Magnetic Bubbles

IP.com Disclosure Number: IPCOM000080893D
Original Publication Date: 1974-Feb-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+2]

Abstract

A light beam is used to probe a magnetic bubble. The bubble's presence is detected by the anisotropy in the Seebeck coefficients, due to the bubble's magnetization resulting in a voltage.

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Electrical Sensing of Magnetic Bubbles

A light beam is used to probe a magnetic bubble. The bubble's presence is detected by the anisotropy in the Seebeck coefficients, due to the bubble's magnetization resulting in a voltage.

It has been determined heretofore that the detection of the state of magnetization of a material electrically can be achieved by probing with a pulsed focused laser beam. The laser beam creates a temperature gradient which is normal to the direction of the film. The direction and strength of magnetization within the film produces a rearrangement of electrical charge in the presence of the gradient to produce a voltage.

A special structure is described herein that enables sensing of a bubble which is brought into a narrow channel, as illustrated in the drawing. The channel is electrically connected to a fast oscilloscope or electronic pulse counter. In the presence of the magnetized material, the pulsed laser beam will strike the region in the channel and produce a pulsed voltage. Correlation of the timing of the bubble through the passage and the pulsing of the laser can be achieved with a suitable contact unit, not shown. The system requires that the magnetization of the bubbles have the same direction relative to the electrodes. Typically, this would be spin up or down. The size of the bubbles would have to be in the micron range.

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