Bloch-line memory element and RAM memory

Abstract

The present invention relates to a Bloch-line memory element and a nonvolatile RAM memory using such a Bloch-line memory element. The Bloch-line memory element comprises a planar magnetic memory element having magnetic domains separated by a wall which contains a Bloch-line disposed within the individual memory element. Coincident write lines interact with the magnetic element for writing a Bloch-line to a predetermined area within the memory element. For sensing the presence or absence of a Bloch-line within the predetermined area, one write conductor and a sense line are used for determining the logic state of the particular memory element. A plurality of memory elements are disposed in an address matrix and can be selected for reading from or writing to the particular Bloch-line RAM memory element for determining or writing bits of words.

I claim: 
     
       1. A random access bi-stable Bloch-line memory element having a standard deviation of the switching field below 5 percent comprising: a discrete planar magnetic memory element having magnetic configuration consisting of a movable bi-stable Bloch-line disposed within the memory element whereby a one or a zero is specified depending on the location of the Bloch-line;   write means coupled to the memory element for applying a magnetic field to a predetermined portion of the memory element; and   read means for determining whether the movable bi-stable Bloch-line is disposed within the predetermined portion of the memory element.   
     
     
       2. The Bloch-line RAM element of claim 1 wherein the write means and the read means further comprise the spatial conjunction of a pair of matrix conductors, each having less than a full address/select capability and at least a half address/select capability. 
     
     
       3. The Bloch-line RAM element of claim 2 wherein the magnetic layer is placed below the leads of the write/read means. 
     
     
       4. The memory of claim 1 wherein the memory elements are electrically disposed within a matrix and the read means and the write means are addressable for selection of a specific memory element. 
     
     
       5. A random access memory system having a standard deviation of the switching field below 5 percent in which binary data is individually stored as a bi-stable Bloch-line within a predetermined portion of the memory of the memory element, bounded by write/read means with the read means further comprising magneto-resistive determination of the presence of or absence of the Bloch-line within the predetermined portion of the memory element, and the read/write means further comprising two or more spatially conjunctive leads each having less than full write capability and each being individually addressable in a matrix array. 
     
     
       6. A random access bi-stable Bloch-line memory system having a standard deviation of the switching field below 5 percent comprising: XY discrete memory elements arranged electrically in an X row, Y column matrix array, each memory element formed a magnetizable material having a bi-stable Bloch-line formed therein;   a plurality of discrete low resistance coupling elements serially electrically coupling Y discrete memory elements for forming Y discrete memory elements per memory column;   column/row read means for coupling a column read current to a selected one of said Y memory columns, said column read current signal serially flowing through said discrete low resistance electrically intercoupling elements and said electrically intercoupled X discrete memory elements therebetween as determined by selection means; and   readout means coupled to the one selected memory element at the intersection of the one selected row line and the one selected memory column for determining by circuit electrical resistance and the presence or absence of a Bloch-line disposed within the sensing area on the discrete memory element.   
     
     
       7. A Bloch-line random access memory system having a standard deviation of the switching field below 5 percent with the capability of writing data in and nondestructively reading data out, comprising: a memory including a plurality of juxaposed columns of memory cells arranged in an array having a plurality of juxaposed rows of conductors operatively connected to a plurality of juxtaposed columns of conductors for writing into the memory cells and reading out of the memory cells logic "ones" and logic "zeros" wherein the presence of a bi-stable Bloch-line in a predetermined sensing area of the memory element corresponds to one of the logic states and the absence of the Bloch-line within the predetermined sensing area corresponds to the other of the logic states;   row means operatively connected to the plurality of juxaposed rows of conductors for selecting and driving a particular one thereof during a write or read operation based on a predetermined address;   column means operatively connected to the plurality of juxaposed columns of conductors and the plurality of juxaposed columns of memory cells for selecting and driving a particular one of the juxaposed meandering columns of conductors during a write operation or a read operation based on a predetermined address;   said row means and said column means cooperating during the write operation to generate coincident drive currents the polarities and amplitudes of the drive currents depending on whether a logic "zero" or a logic "one" is to be written, and said column means cooperating during the read operation to enable a current flow through the particular selected one of the memory elements; and   data readout means the input of which is operatively connected to the plurality of juxaposed columns of memory cells of said memory element such that when the particular one of the plurality of juxtaposed columns of memory cells is selected and the particular one of the plurality of juxaposed rows of conductors is selected, the logical contents of memory cell at that location is read by determination of the electrical resistance of the cell depending on the presence or absence of a Bloch-line within the sensing area of the memory element.   
     
     
       8. A random aces bi-stable Bloch-line memory having a switching field standard deviation below 5 percent comprising: a planar element made of permalloy material, said planar element being shaped similar to a ten-sided bi-directional barbed arrowhead symmetrical about a longitudinal axis and having a first and second end along the longitudinal axis with one of said ends being more pointed than the other, and having a constriction across the width disposed approximately at the middle of the shape along the longitudinal axis and   means for reading and writing to said memory element.   
     
     
       9. The random access memory element of claim 8 wherein a plurality of said elements are disposed in an addressable memory matrix. .Iadd. 
     
     
       10.  In a random access memory including a plurality of discrete memory cells having localized magnetic fields therein with magnetic domains separated by walls containing Bloch-lines, the improvement residing in: write means coupled to the memory cells for switching the localized magnetic fields therein between different intensity levels causing the Bloch-lines to move between different locations within each of the memory cells and sense means coupled to the memory cells for sensing presence or absence of the Bloch-lines at said locations within the respective memory cells to read out data stored in the memory cells..Iaddend.