Abstract: A memory device utilizing magnetic bubbles which are driven by a rotary magnetic field on contiguous disc drive patterns. These disc patterns have mainly a first scale. Each drive pattern also comprises a further disc pattern of a substantially larger scale. These further disc patterns each time comprise an excitation loop. These loops are mutually staggered with respect to the phase of the rotary field and are electrically connected in series. The series connection can be excited during relevant phases of the rotary magnetic field in order to selectively process a bubble then present in a locally formed preferred position from among the magnetic bubbles present on the larger disc patterns. The processing operation may be generating, detecting and annihilating bubbles.

Abstract: A current stretch detection method for a bubble device in which bubbles are written at least one bit apart. A stretch pulse is applied to a stretch conductor so that when a bubble is detected, it is maintained stretched, even though the bubble following it has moved one bit. Preferably the stretch pulse is of a convex-shape. A bubble device has a hairpin stretch conductor and a detecting element disposed centrally in the conductor. The terminal of the detecting element on the higher potential side is arranged so that it does not cross the stretch conductor. The contiguous propagation pattern is provided with a notch at a position in which the stretch conductor is located.

Abstract: A magnetic bubble store formed of a series of longitudinally oriented shift registers and at least one transversely oriented access contour register having a single access point corresponding to each access end of each longitudinally oriented shift register, wherein magnetic bubbles are displaced in the longitudinally oriented shift registers by applying a rotary magnetic field thereto, and wherein magnetic bubbles are displaced in the transversely oriented access contour register by applying an electric current thereto. The longitudinally oriented registers are formed of motifs defined by ion implantation in a magnetic garnet layer.

Abstract: A passive annihilator for ion-implanted contiguous-disk bubble devices has a deep cusp formed by two narrow, non-implanted regions. This annihilator has a maximum bias field margin and drive field margin, and is compatible with other components which comprise a functional ion-implanted contiguous-disk bubble device.

Abstract: A magnetic bubble memory device includes: a magnetic layer with a first region having an easy axis of magnetization extending in a certain direction and a second region surrounding the first region and having an easy axis of magnetization substantially perpendicular to that of the first region, said first region defining a plurality of bubble propagation patterns; and a replicate gate with a stretch conductor pattern, to which an electric current is applied so as to stretch a bubble between said propagation patterns, and a cutting pattern formed in the second region between the propagation patterns and adapted to lower the bubble collapse field so as to cut the stretched domain. The replicate gate is operated by applying an operating current pulse to the stretch conductor pattern, said operating pulse including a stretch pulse for stretching the bubble and a cut pulse, following the stretch pulse, for cutting the stretched domain.

Abstract: A magnetic bubble domain system including a planar layer of magnetic material in which magnetic bubble domains can be propagated; and first and second bubble domain guide structure coupled to the layer and defining respective first and second bubble propagation paths for guiding the movement of bubbles in the layer in response to a cyclical change in the orientation of a reorienting magnetic field within the plane of the layer. A transfer bubble domain guide structure coupled to the layer is also provided for transferring bubble domains between the first and the second propagation paths responsive to a reverse in direction of the reorienting magnetic field. The transfer path is substantially the same as one of the directions of the crystallographic axes of the planar layer.

Abstract: A replicator for an ion-implanted magnetic bubble domain device including a single level conductor bubble cutting element disposed between first and second spaced apart bubble domain guide structures. The charged wall movement in response to the rotating in-plane field functions to stretch a bubble domain travelling along the first bubble propagation path onto the second bubble propagation path and the conductor element crossing the stretched domain functions in response to an activating signal on the conductor to cut the bubble.

Abstract: A magnetic bubble memory device comprises: a magnetic layer which has a first region having the easy axis of magnetization extending in a certain direction and a second region surrounding said first region and having the easy axis of magnetization substantially perpendicular to that of the first region, said first region defining at least one major loop pattern for propagation of information bubbles and a plurality of minor loop patterns for storage of information bubbles; and an electrical conductor pattern deposited on said magnetic layer in a region in which the major loop pattern and the minor loop patterns are opposed to each other, thereby constructing a transfer gate. The major loop pattern is provided, at the portions thereof substantially opposed to the ends of the minor loop patterns in the transfer gate, with gaps through which the bubbles are transferred between the major loop pattern and the minor loop patterns. The transfer gate is driven by means of a convex-shaped pulse of transfer current.

Abstract: A gap tolerant merge element insensitive to crystallographic orientation has a first input track with an end portion substantially facing the end portion of a second input track to form a merge region. The straight edge region in the end portion of the first input track is of a different length than the straight edge region in the end portion of the second input track that it faces.

Abstract: A bubble domain replicator for ion-implanted contiguous disk devices has a cusp portion and a tip portion extending substantially away from the cusp portion so that the cusp forms part of a super track and the tip forms part of a bad track. A hairpin conductor is positioned over the cusp portion and tip portion so that the closed end of the hairpin is closest to and surrounds the end of the tip portion.

Abstract: A magnetic bubble detector for an ion-implanted bubble memory is achieved by using a permalloy detector element and two conductors. The conductors are operative first to stretch a bubble from one position in a bubble path and then to destretch it, after detection, from the detector element to another position in the path. The detector has been operated at 100 kilohertz.

Abstract: An improved non-data reversing one-way bubble transfer switch for contiguous disks is disclosed. The switch has a conductor arrangement in which one edge of the conductor is substantially concentric with and overlapping with the major loop which is in the form of a plurality of scallops. The major loop extends in a direction substantially transversely to one of the three primary crystallographic axes in the bubble material so as to have a propagation track with a high margin on one side and a low propagation margin on the other side. The tip of a minor loop end portion is aligned substantially concentric with the scalloped concave portion of the major loop. This switch has a maximum bias field margin and a maximum phase margin.

Abstract: A replicator for a magnetic bubble domain device including a hairpin loop conductor element traversing first and second spaced apart bubble domain guide structures. The replicator functions to replicate a bubble domain travelling along the first bubble propagation path onto the second bubble propagation path in response to an activating signal on the conductor. The replicate guide structure includes two attractive cusp positions and one repulsive cusp position, so that the repulsive charged wall formed at the repulsive cusp position functions to sever a stretched bubble domain formed by the activating signal.

Abstract: A gap tolerant merge element for contiguous-disk bubble devices is disclosed. The merge element includes one input track with a tip portion substantially facing the cusp portion of a second input track to form a merge region. An output track is associated with the merge region. In a preferred embodiment, the merge element is passive and does not have a conductor. In another embodiment, the merge element is active and does have a conductor.

Abstract: A swap gate for ion-implanted contiguous disk bubble devices using folded minor loops is disclosed. The bubble device has a major loop, a folded minor loop and a swap element positioned between the major loop and the folded end of the minor loop. The swap element has a first portion for interchanging bubbles with the major loop, a second portion for receiving bubbles from a first region of the folded end of the minor loop, and a third portion for transferring bubbles from the first portion to a second region of the folded end of the minor loop. The folded end of the minor loop also has a third region positioned between the first and second regions to form two bubble storage locations. The bubble device has a conductor associated with the major loop and the first portion of the swap element to form a first transfer gate. The device also includes a second conductor associated with the folded minor loop and the second portion of the swap element to form a second transfer gate.

Abstract: A conductorless swap gate for ion-implanted contiguous-disk bubble devices using a folded minor loop and means for reversing the rotation of the rotating magnetic field is disclosed. The bubble device has a major loop, a folded minor loop, a swap gate containing at least one element positioned between the major loop and the folded end of the minor loop. The swap gate has a first portion for interchanging bubbles with the major loop, a second portion for transferring bubbles from a first region of the folded end of the minor loop, and a third portion for receiving bubbles from the second region of the folded end of the minor loop. Activation of the means for reversing the rotation of the rotating magnetic field causes the swap function to be effected. In a preferred embodiment, the device has a swap gate that has two elements and functions as a true swap gate.

Abstract: A method for processing a magnetic bubble domain device for hard bubble suppression comprising the steps of providing a non-magnetic substrate; providing a thin layer of magnetic material capable of supporting magnetic bubble domains on a first major surface of the substrate; and directing a beam of ions consisting essentially of a nongaseous ion at the substrate.

Abstract: Magnetic devices exemplified by bubble devices depend upon functional magnetic layers initially produced by epitaxy and reduced to effectively thinned surface layers by ion implantation. Implantation is at well-defined energy spectral levels which minimize effect on surface layers and which predominantly affect a "buried layer". As a result, such affected layer acts as a boundary layer of a functional layer which is spaced away from an interface between a substrate and a deposited layer.Commercial significance is primarily concerned with high bit density devices in which effectively thinned regions are less than 3 micrometers in thickness.

Abstract: A magnetic bubble domain device including a segmented stretcher detector. The detector is formed from a propagation path for magnetic bubble domains, and a first replicator disposed adjacent the propagation path. The first replicator functions to replicate one of the propagating bubble domains into a pair of magnetic bubble domains, and to transfer one of the bubble domains into a first secondary track extending in a direction different from the direction of the propagation path. A second replicator is disposed along the propagation path and functions to replicate the one bubble domain into a pair of magnetic bubble domains and to transfer one of the bubble domains into a second secondary track extending generally in the first direction. Finally, the detector is disposed along the first direction and functions to detect the plurality of magnetic bubble domains.

Abstract: Transfer between paths in ion-implanted magnetic bubble memories has been achieved without the use of transfer conductors. The transfer mechanism takes advantage of the three-fold anisotropy of the implanted drive layer which makes it possible for bubbles to pass freely through gaps in one direction while being obstructed from passing through in the other direction. Transfer is controlled by a brief reversal of the direction of rotation of the in-plane field. In one embodiment, a bidirectional transfer gate is employed. Configurations using unidirectional gates and hybrid gates using conductor and reverse-rotation controlled transfer are also shown.

Abstract: In ion-implanted bubble memories where a patterned ion-implanted layer defines the propagation paths and the special functional elements, a uniform additional ion implant layer provides for a high degree of control over the nucleation level in the bubble material. Design flexibility and high generator margins are achieved.

Abstract: A magnetic bubble device in which ions are implanted, under different conditions, in at least two kinds of regions of a magnetic thin film serving as a medium for propagation of a magnetic bubble. In this manner, the operating margins of magnetic bubble stable operation regions of respective functional parts of the device are made nearly equal, thereby providing for improved operating margin of the device as a whole.

Abstract: A propagation track for use in contiguous disk bubble devices consists of a plurality of spaced dovetail shaped elements which are connected at one end thereof by a track portion which faces in the direction of and is substantially perpendicular to the (1,1,2) axis. The first, third and fifth sides of the dovetail structure are elongated and also face in the direction of and are substantially perpendicular to the (1,1,2) axis. The remaining sides of the dovetail structure have different orientations, the second side facing in the direction of and being substantially perpendicular to the (2,1,1) axis, and the fourth side facing in the direction of and being substantially perpendicular to the (1,2,1) axis. The orientation of the two cusps formed by the first and second sides and the fourth and fifth sides is such that the lines bisecting and pointing toward the cusps are substantially parallel to the (1,2,1) and (2,1,1) axes, respectively.

Abstract: A magnetic bubble domain structure comprising a bubble domain layer supported by a nonmagnetic substrate. A control layer is superimposed on the major surface of the domain layer which remote from the substrate. The control layer has an easy axis of magnetization in the plane which defines at least one bubble domain propagation path. The unique control layer according to the invention may be a garnet layer which comprises two sublayers: a first, continuous, sublayer, and a second, discontinuous, sublayer. The discontinuous sublayer defines the required propagation patterns. An advantage of the invention is that the in-plane rotary field to be applied for propagating the bubble domains can be considerably weaker than in bubble domain structures which are equipped with nickel-iron propagation patterns.

Abstract: A propagation pattern for contiguous disk bubble devices consists of a plurality of parallel propagation tracks in which each propagation track is asymmetric. Adjacent propagation tracks are positioned so that the cusps that face each other are aligned therewith. The region between adjacent tracks forms two subregions which are mirror images of each other when the region is bisected by a longitudinal midplane.

Abstract: Operating margins for major-minor magnetic bubble memories are improved by use of protective rails between minor loops to prevent loss of information due to stripout. The rails, as are the propagation paths, are defined by unimplanted regions in an otherwise ion-implanted layer. In another embodiment, unimplanted rectangular islands are used rather than rails.

Abstract: A technique and structure is described in which bubble domain devices can be made, and particularly bubble domain devices comprisng contiguous propagation elements. A thin magnetoresistive layer, such as permalloy, is blanket deposited over a substrate including a bubble domain film, and is then selectively "poisoned" to destroy its magnetization except in those areas where thin sensors are to be provided. The poisoned portions of the magnetoresistive layer serve as a plating base for conductor metallurgy which can be used as an ion implantation mask, and for carrying electrical current. This eliminates some process steps which had been required in the prior art, and does not leave magnetic permalloy in those areas of the bubble domain chip were they would adversely affect propagation of domains by ion implanted contiguous propagation elements. This technique can also be used to make bubble domain devices having gapped propagation elements.

Abstract: A gap between sets of contiguous discs defined by nonimplanted regions in an otherwise ion-implanted bubble layer allows an isolation between bubbles which leads to the achievement surprisingly close spacing between neighboring bubble paths. The misalignment of the gap axis with an axis of symmetry of the bubble layer is an important consideration in realizing the isolation.

Abstract: A bubble storage system using contiguous propagation elements is described using magnetically soft drive layers for movement of the bubble domains in a bubble domain film, in response to the reorientation of a magnetic drive field in the plane of the drive layers. In contrast with prior art contiguous element propagation structures, charged walls are not employed for movement of bubble domains. Instead, magnetic poles along the drive layers are used to move the domains. Two drive layers are used, each of which is comprised of a magnetically soft material, such as permalloy. The drive layers are located at different heights with respect to the layer in which the magnetic bubble domains exist, the bottom drive layer being comprised of contiguous propagation elements defining a generally undulating edge along which the magnetic bubble domains move. This layer can be comprised of permalloy contiguous disks, diamonds, etc.

Abstract: A gap between sets of contiguous discs defined by unimplanted regions in an otherwise ion-implanted bubble layer allows a merge function to be achieved. The alignment of the gap axis with an axis of symmetry of the bubble layer and the width of the gap are important considerations in the performance of the merge.

Abstract: An improved magnetic domain generator for a magnetic arrangement employing a layer of garnet in which single wall domains (bubbles) are moved by an in-plane rotating magnetic field. A first domain generator includes a first propagation circuit for moving bubbles away from the generator when the rotating field is in a first direction. A second domain generator includes a second propagation circuit for moving bubbles away from the second generator when the rotating magnetic field is in an opposite direction to the first direction. The two generators are coupled to a common pulse source which is able to provide pulses at twice the rate of rotation of the magnetic field. In this manner, two independent streams of bubbles may be produced by the generators from a single pulse source.

Abstract: Guard rails are described for particular use with magnetic bubble domain chips using contiguous propagation elements. These guard rails generally surround the active device area (storage area) of the chip and are used to move stray bubble domains from the storage area to the edge of the chip, or to a collapser etc., and also to prevent stray bubbles from entering the active device area. These guard rail structures are comprised of contiguous propagation elements characterized by an undulating edge and a smooth edge, both of which generally move bubble domains away from the active device area in response to the reorientation of the same magnetic drive field. In one embodiment, the guard rail is a spiral structure surrounding the active device area, having one end in the interior of the magnetic bubble chip adjacent to the active device area, and another end near the edge of the chip, or near a bubble annihilator, etc.

Abstract: A replicator for an ion-implanted magnetic bubble memory includes an offset hairpin geometry. The conductor is associated with features in adjacent bubble paths which exhibit strong attracting poles at the same time. The conductor stretches the bubble between the attracting poles. The bubble is severed by the reorienting propagation field.

Abstract: A magnetic bubble memory of the G-shaped organization is implemented by ion-implantation. Attractive operating margins are realized by the use of transfer-out arrangements which moves bubbles in parallel first to an auxiliary path and thereafter to the major loop in a manner to invert the data.

Abstract: In magnetic bubble domain chips using layers of crystalline material having in-plane magnetization for propagation, hard bubble suppression, etc., asymmetric propagation often results due to crystalline anisotropies in the layer of in-plane magnetization. In these chips, different propagation margins result for propagation in different directions with respect to the crystalline axes of the in-plane layer. In the present magnetic chip, a plurality of shift registers is provided for movement of bubble domains in a plurality of directions, all of which provide good propagation margins. The registers are aligned in particular directions with respect to the directions of easy stripout of bubble domains in order to avoid the problem of asymmetric propagation. Examples are shown using ion implanted contiguous element propagation patterns organized in a major/minor loop type of storage organization.

Abstract: The familiar G-shaped, non-closed, major path in a major-minor, magnetic bubble memory is formed controllably into a closed circumferential major loop about the minor loops during operation. A simple data format allows a simple start-up algorithm to ensure that data are secured.

Abstract: The discovery of a magnetoresistive effect in oriented, crystalline, semiconducting iron garnet materials is used to design devices which detect the presence or orientation of magnetic fields. The principal measure of this effect is that the resistance between two electrodes (12) on the garnet body (11) varies as an imposed magnetic field (14, 15) produces a change in the direction of the magnetization of the body (11). This effect is useful when the garnet is so constituted as to possess a resistivity from 10.sup.3 to 10.sup.7 ohm-centimeters. Also, the anisotropy field of the garnet body must be comparable to less than the magnitude of the magnetic field to be detected. One aspect of particular utility for magnetic "bubble" detectors (in magnetic bubble memories) is the isotropic character of the resistance when the magnetization is varied in the (111) plane but the significant change of resistance when the magnetization is moved to the [111] direction.

Abstract: Magnetic bubble functional elements are implemented by aperture patterns in a single layer of electrically-conducting material. The operations of the elements are compatible with single-level conductor driven bubble memories described in A. H. Bobeck patent applications, Ser. Nos. 857,921 now U.S. Pat. No. 4,143,419 issued Mar. 6, 1979 and 856,925, filed Dec. 6, 1977, and in A. H. Bobeck-F. J. Ciak patent application, Ser. No. 899,578, filed Apr. 24, 1978 now abandoned.

Abstract: A bubble domain storage system is described which has the best features of contiguous element bubble propagation systems and bubble lattice file systems. An array of magnetic bubble domains, such as a lattice, is moved along contiguous propagation patterns in response to the reorientation of a magnetic field in the plane of the bubble domain film. Adjacent rows of bubble domains in the array move in opposite directions to provide individual storage loops within the array. Information accessing can be achieved by the use of input/output registers similar to those used in other contiguous disk bubble domain storage systems. For example, the storage system can be a conventional major/minor loop organization using contiguous element propagation patterns for the storage registers and for the input/output registers.

Abstract: A magnetic bubble storage system and a method for making it using only two masking steps, one of which is critical. In a preferred embodiment, the storage regions are comprised of ion implanted propagation elements which can be contiguous with one another. The functions of write, read, storage, transfer between storage elements in different shift registers, and annihilation are provided by the method in which the same mask is used to define ion implanted regions and for formation of conductor metallurgy. Permalloy bridges over ion implanted regions are used to provide transfer of information between one storage element and another. In a preferred embodiment, NiFe is used for sensing, annihilation, and transfer of information, while the storage registers are comprised of ion implanted regions defining contiguous propagation elements of generally circular geometry.

Abstract: In a display unit utilizing magnetic bubbles, selective extinction of the magnetic bubbles in a matrix results in a pattern of letters and/or images which are combinations of the magnetic bubbles as picture elements. The present display unit has in-plane anisotropic areas each of which has an easy magnetization axis parallel to the surface of the magnetic bubble material thin film produced by attaching the magnetically soft thin film on the magnetic bubble accommodation spaces in the magnetic bubble material thin film or by ion-implanting into the given spaces of the magnetic bubble material garnet. Therefore, according to this invention, the domain walls of the magnetic bubbles are attracted to said in-plane anisotropic areas and securely held at predetermined picture element positions.

Abstract: A method for detecting the wall state of a soft bubble based upon the collapse characteristics of the bubble domain on a layer of bubble domain supporting material is described. The method includes the step of exchange coupling a magnetic layer, for example, an ion-implanted layer, to the bubble supporting layer. An in-plane field is applied to the bubble supporting layer when Bloch lines are present in the bubble domains. The bias field and the pulse field are set at a level to form a range of pulse widths which are suitable for the discrimination of soft bubble domains having different wall states. A pulse is then applied for a time sufficient to collapse only the S=1 bubble and not the S=0 bubble. Thereby this method distinguishes S=0 bubbles having one pair of winding Bloch lines from S=1 bubbles having one pair of unwinding Bloch lines. This method also distinguishes S=1 bubbles having a clockwise chirality from S=1 bubbles having a counterclockwise chirality.

Abstract: A conductor-access, magnetic bubble memory is realized with a single metallization level for propagation. The familiar undulating or serpentine conductor pattern used for moving bubbles is modified to allow a simple and easily realizable, low power drive arrangement where currents flow parallel to the bubble paths.

Abstract: A conductor-access magnetic bubble memory is realized with a single electrically-conductive film for the propagation of bubbles. The film is characterized by sequences of apertures in the film. The sequences define paths for bubble movement in response to controlled current pulses. Ion-implanted regions offset with respect to the aperture edges ensure unidirectional bubble movement along the paths.

Abstract: A magnetic bubble memory with a single electrically-conducting layer for defining a bubble propagate arrangement is adapted to provide a compatible bubble expander detector by a sequence of increasingly larger apertures in the conducting layer.

Abstract: A switch for transferring magnetic bubble domains from one propagation path to another using a magnetic charged wall is described. The magnetic charged wall bridges the two propagation paths and causes the domain to strip out along the charged wall. By pulsing an overlying conductor, the charged wall and the associated strip domain will shrink away from one side of the conductor in order to translate the domain to the other side. In contrast with previous transfer gates using current carrying conductors where the magnetic field produced by current through the conductors served as the major bubble translational force, the present switch utilizes a magnetic charged wall as the driving source, the current through the conductor being used only for modification of the charged wall. Therefore, the switching margins are maximized to be substantially the same as the bubble propagation margins and the switching currents required are reduced from those in previously used transfer gates.

Abstract: An improved magnetic bubble domain nucleator is provided which uses a magnetic wall, such as a charged wall, Neel wall, or Bloch wall, to assist nucleation. In a preferred embodiment, a magnetic charged wall is produced in an ion implanted region of a magnetic material with an in-plane magnetic field, and an applied nucleating magnetic field is produced by current in a conductor. The combination of the first magnetic field associated with the charged wall and the second magnetic field produced by current through the conductor is sufficient to nucleate a bubble domain in the magnetic medium whereas each of these fields acting alone is not sufficient for nucleation. Since the first magnetic field provides a component of the total nucleating field, the amount of nucleation current required in the conductor is reduced.

Abstract: A laminated, integral structure that forms a bubble memory plane for the generation, storage and transfer of single wall domains, bubble domains or bubbles is disclosed. The memory plane is formed of a non-magnetic gadolinium gallium garnet (GGG) support member; formed upon the support member is a magnetizable layer that is capable of sustaining stripe domains; formed upon the stripe domain layer is a non-magnetic gadolinium gallium garnet (GGG) spacer layer; and, formed upon the spacer layer is a magnetizable layer in which single wall domains or bubbles are capable of being generated, sustained and transferred from one position to another along a planar dimension of the bubble domain layer.

Abstract: An apparatus for and a method of propagating bubble domains is disclosed. The apparatus includes a memory plane that is comprised of a non-magnetic support member upon which are formed a bubble domain layer and at least one stripe domain layer. The stripe domain layer has a set of relatively-narrow, periodic, potential well generating fixed stripe domains provided therein while the bubble domain layer has a set of relatively-wide, parallel, potential well generating fixed guidance channels provided therein that are oriented orthogonal to the parallel set of stripe domains in the stripe domain layer. Bubble domains are concurrently entered, in parallel, at one end of the memory plane in selected ones of the guidance channels. A periodic amplitude modulated bias field of frequency F propagates each of the bubble domains along the associated guidance channel from adjacent to next downstream adjacent stripe domain and thus through the memory plane at the frequency F.

Abstract: Magnetic bubble memory chips herein are characterized by circuits of permalloy and/or electrical conductors which include patterns designed to be sacrificed if electrical charges build up during processing or handling. Improved chip yield results.