Browse Prior Art Database

Superconducting Bubble Domain Detector

IP.com Disclosure Number: IPCOM000078206D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 3 page(s) / 54K

Publishing Venue

IBM

Related People

Almasi, GS: AUTHOR [+4]

Abstract

Figs. 1A, 1B, 2, 3 show various configurations for a superconducting element used to detect magnetic bubble domains. This element is located in close proximity to the magnetic sheet in which the bubble domains exist and is in flux-coupling proximity to these domains. Since the superconducting critical current through the weak links in the superconducting detector is a function of the magnetic field in the flux area hole in the detector, the presence and absence of domains will affect this critical current. When a domain is in the flux-area hole, the total magnetic field across the superconducting detector changes and this switches the critical current state of the detector.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Superconducting Bubble Domain Detector

Figs. 1A, 1B, 2, 3 show various configurations for a superconducting element used to detect magnetic bubble domains. This element is located in close proximity to the magnetic sheet in which the bubble domains exist and is in flux-coupling proximity to these domains. Since the superconducting critical current through the weak links in the superconducting detector is a function of the magnetic field in the flux area hole in the detector, the presence and absence of domains will affect this critical current. When a domain is in the flux-area hole, the total magnetic field across the superconducting detector changes and this switches the critical current state of the detector. This change in critical current state can be detected, by putting a constant-read current through the detector and sensing the voltage drop across the detector when its state changes.

In Figs. 1A (top view) and 1B (side view) a double-film detector is provided, in which two superconducting films are separated by two weak link oxide barriers. These barriers are about 10-20 Angstroms thick.

In Fig. 2, a single superconducting film detector is shown having constricted "point" contacts which form the Josephson weak links in the structure.

In Fig. 3, a double wire or double-film detector is shown, in which two thin superconducting wires are separated at two locations by Josephson weak links. In this case, the weak links are formed by the natural oxide of the bottom wire or thin film.

This type of detector is particularly advantageous in a random-access memory, where many detectors exist in series. Since there is zero resistance in the absence of a domain, many sensors can be connected in series without losing sensitivity. In Fig. 4, w...