Propagation of magnetic domains by self-induced drive fields

Claim 2

A magnetic domain propagation device comprising: a magnetic layer having one direction of magnetization and at least one magnetic domain having an opposite direction of magnetization movable in said magnetic layer; a drive layer overlaying said magnetic layer in a magnetic coupled relationship, said drive layer conducting a uniform current therethrough when an electric field is applied to said drive layer; a pair of electrodes connected to said drive layer for connection to a voltage source effective to apply an electric field such that said uniform current is developed with a substantially uniform density having a magnitude responsive to the magnitude of said electric field; and current altering means responsive to the magnetization of a magnetic domain in said magnetic layer so as to vary the uniform current density of said drive layer and define a region of perturbed current adjacent said magnetic domain, said perturbed current being effective to produce a resultant drive magnetic field for moving said magnetic domain in said magnetic layer at a velocity responsive to the magnitude and direction of said uniform current.

Claim 3

The magnetic domain propagation device as claimed in claim 1 wherein said drive layer includes a piezoresistance material and wherein said current altering means includes a layer of magnetostrictive material is bonded to said drive layer so as to be disposed between said drive layer and said magnetic layer, whereby the magnetization of said magnetic domain in said magnetic layer effects a deformation in said layer of magnetostrictive material so as to in turn deform said drive layer in a region adjacent said magnetic domain and to change the conductivity of said drive layer to produce said region of perturbed current for effecting said resultant drive magnetic field.

Claim 4

The magnetic domain propagation device as claimed in claim 1 wherein said drive layer includes a photoconductance material, and wherein said current altering means includes first and second polarizing filters with said first polarizing filter being disposed between one face of said magnetic layer and said drive layer and said second polarizing filter disposed on an opposite face of said magnetic layer, whereby said opposite magnetization of said magnetic domain alters polarized light passing between said magnetic layer and said drive layer so as to vary the conductivity of said drive layer in a region adjacent said magnetic domain to thereby produce said region of perturbed current and to effect said resultant drive magnetic field.

Claim 5

A magnetic domain propagation device comprising: a magnetic layer having a given direction of magnetization and at least one magnetic domain having a different direction of magnetization and being movable in said magnetic layer; a drive layer overlaying said magnetic laYer in a magnetic coupled relationship, said drive layer having a uniform current conducting characteristic; means applying an electric field effective to develop a uniform current of uniform density in said drive layer, said uniform current having a magnitude and direction directly responsive to the magnitude and direction of said electric field, said different direction of magnetization of said magnetic domain in said magnetic layer being effective to alter the uniform current density of said drive layer in a region of perturbed current immediately adjacent said magnetic domain, and said region of perturbed current being effective to produce a resultant drive magnetic field acting through said magnetic coupled relationship so as to move said magnetic domain in said magnetic layer at a velocity responsive to the magnitude and direction of said uniform current.

Claim 6

A magnetic domain propagation device comprising: a magnetic layer having a given direction of magnetization and at least one magnetic domain having a different direction of magnetization and being movable in said magnetic layer; a drive layer overlaying said magnetic laYer in a magnetic coupled relationship, said drive layer having a uniform current conducting characteristic; means applying an electric field effective to develop a uniform current of uniform density in said drive layer, said uniform current having a magnitude and direction directly responsive to the magnitude and direction of said electric field, said different direction of magnetization of said magnetic domain in said magnetic layer being effective to alter the uniform current density of said drive layer in a region of perturbed current immediately adjacent said magnetic domain, and said region of perturbed current being effective to produce a resultant drive magnetic field acting through said magnetic coupled relationship so as to move said magnetic domain in said magnetic layer at a velocity responsive to the magnitude and direction of said uniform current.

Claim 7

The magnetic domain propagation device as claimed in claim 4 wherein said drive layer includes a magnetoresistive material, and wherein said different direction of magnetization of said magnetic domain alters the conductivity of said drive layer in a region immediately adjacent said magnetic domain to produce the region of perturbed current therein.

Claim 8

The magnetic domain propagation device as claimed in claim 4 wherein a damping plate layer made of an electrically conductive material extends across said magnetic layer to retard the velocity of travel of said magnetic domain.

Claim 9

The magnetic domain propagation device as claimed in claim 4 wherein said drive layer includes a semiconductor material having a high electrical carrier mobility so as to have a Hall effect like characteristic whereby said different direction of magnetization of said magnetic domain alters the uniform current density of said drive layer due to the effect of the magnetization of said magnetic domain upon the carriers forming said uniform current density in said drive layer thereby altering said uniform current density in a region adjacent said magnetic domain to produce said region of perturbed current and thereby produce the resultant induced drive magnetic field.

Claim 10

The magnetic domain propagation device as claimed in claim 4 including an external control magnetic field source directed to said drive layer for reorienting the direction of the uniform current density therein so as to vary the orientation of said perturbed current and thereby vary the effect of said resultant magnetic drive field for varying the direction in which the magnetic domain moves.

Claim 11

A magnetic domain propagation device as claimed in claim 8 including a first input signal source controlling the external control magnetic field in response to a first input signal and further including a second input signal source controlling the intensity of said electric field and said drive layer in response to a second signal applied thereto whereby the velocity of propagation of a magnetic domain in said magnetic layer is responsive to the product of said first and second input signals.

Claim 12

A magnetic domain propagation device as claimed in claim 9 wherein said first and second input signals are sinusoidally varying alternating current signals whereby the velocity of propagation of said magnetic domain corresponds to the product of the instantaneous magnitudes of said first and second input signal times the cosine of the phase angle between said first and second input signals.

Claim 13

The magnetic domain propagation device as claimed in claim 4 including another drive layer overlaying the magnetic layer along a face opposite of that overlaid by the first named drive layer, said another drive layer having a uniform current conducting characteristic, means for applying another electric field effective to develop a uniform current of uniform density in said another drive field, said last named uniform current having a magnitude and direction directly responsive to the magnitude and direction of said another electric field, whereby the magnetization of said mAgnetic domain produces a region of perturbed current in the uniform current density in said another drive layer immediately adjacent said magnetic domain such that the magnetic domain is propagated in response to both of the first named and another electric field producing the uniform current densities in said first named drive layer and said another drive layer.

Claim 14

A magnetic domain propagation device as claimed in claim 11 wherein first and second pairs of electrodes are included, each pair being disposed on a separate one of the drive layers along mutually non-parallel axes, and wherein first and second voltage sources are included, said first and second voltage sources being connected to said first and second pairs of electrodes respectively, to apply the electric fields to the first named and said another drive layers such that variation of the potentials of said first and second voltage sources correspondingly change the direction of the magnetic domain movement in said magnetic layer.

Claim 15

A magnetic domain propagation device as claimed in claim 4 wherein said magnetic layer includes means for defining a channel through said magnetic layer and wherein said drive layer has a uniform current in a predetermined direction so that said magnetic domain within said channel is moved along said channel by the perturbed current developing the resultant magnetic drive field for producing the desired movement of said magnetic domain along said channel.

Claim 16

A magnetic domain propagating device as claimed in claim 13 wherein said drive layer includes a semiconductor material having a high electrical carrier mobility so as to have a Hall effect like characteristic whereby the magnetization of said magnetic domain alters the uniform current density in a region of immediately adjacent said magnetic domain, wherein said channel is formed in a closed circular path, and wherein an external control magnetic field source directs a magnetic field through said drive layer to effect further alteration of said uniform current such that the magnetic domain is moved by the resultant magnetic drive around said channel.

Claim 17

The magnetic domain propagation device as claimed in claim 13 including a conductor positioned on said magnetic layer at one end of said channel and connected to an input signal source for establishing a magnetic domain at the one end of said channel; and a magnetically responsive detector positioned along said channel and connected to a utilization device for applying an impulse to said utilizing device in response to movement of a magnetic domain past the detector whereby the magnetic domain begins movement at one end of said channel and is moved past said detector at a velocity corresponding to the intensity of said uniform current density of said drive layer.

Claim 18

The magnetic domain propagation device as claimed in claim 15 wherein a pair of detectors including said first named detector are disposed along said channel for intiating impulses responsive to the movement of said magnetic domain within said channel, wherein a timing device is connected to said pair of detectors for measuring the time interval for said magnetic domain to travel between said detectors so as to produce an indication of the velocity of said magnetic domain which is proportional to the intensity of said uniform current density of said drive layer.

Claim 19

A magnetic domain propagation device as claimed in claim 13 wherein said channel includes two sets of magnetic domain propagating elements wherein each set is spaced from the other set a desired length apart, wherein an external magnetic field source is provided for propagating a magnetic domain within said channel along said second sets of elements, and wherein said drive layer is positioned along the length of said channel between said sets of domain propagating elements whereupon a magnetic domain is moved between said first and second sets of magnetic domain propagating elements exclusively in response to the uniform currEnt density of said drive layer.

Claim 20

The magnetic domain propagation device as claimed in claim 17 including a voltage source having a switch means for selectively applying the potential of said voltage source across said drive layer so as to apply said electric field to develop said uniform current density in said drive layer when said switch is closed and to terminate said uniform current density when said switch is open thereby selectively controlling the movement of a magnetic domain moving from said first set of domain propagating elements to said second set of domain propagating elements.

Claim 21

A watthour metering apparatus comprising: a magnetic layer of magnetic domain propagating material having at least one magnetic domain; a drive layer formed of a semiconductor material having a high carrier mobility wherein current in said drive layer is formed by a carrier of one type; means establishing a circular magnetic domain channel in said magnetic layer so as to define a predetermined circular path for said one magnetic domain; a first electrode attached to said drive layer so as to be equally spaced from an inner diameter of said channel, a second electrode positioned on said layer so as to be equidistantly spaced relative to the other diameter of said channel and therefore equidistantly from said first electrode; and a magnetic field source for providing an external control magnetic field to the area of said drive layer intermediate said first and second electrodes; a magnetically responsive domain detecting means mounted in magnetically coupled relationship with said channel of said magnetic layer so as to effect an electrical impulse in response to movement of a magnetic domain in said channel upon passing said detector; a voltage responsive input signal being responsive to the voltage component of an electrical power quantity to be measured and connected across said first and second electrodes so as to establish an electric field in said drive layer in response to the instantaneous magnitude of said voltage component such that a substantially uniform current density is established in said drive layer between said first and second electrodes and adjacent said channel; a current responsive input signal responsive to the current component of the power quantity to be measured by said apparatus and connected to said magnetic field source so as to control said external control magnetic field in response to the instantaneous magnitude of said current component and to orient said uniform current density in response thereto whereby said magnetic domain is propagated at a velocity proportional to the product of the voltage and current power components and the number of impulses generated by said detector is proportional to watthours of electric energy of the measured electrical power.

Claim 22

A watthour metering apparatus comprising: a magnetic layer of magnetic domain propagating material having at least one magnetic domain; a drive layer formed of a semiconductor material having a high carrier mobility wherein current in said drive layer is formed by a carrier of one type; means establishing a circular magnetic domain channel in said magnetic layer so as to define a predetermined circular path for said one magnetic domain; a first electrode attached to said drive layer so as to be equally spaced from an inner diameter of said channel, a second electrode positioned on said layer so as to be equidistantly spaced relative to the other diameter of said channel and therefore equidistantly from said first electrode; and a magnetic field source for providing an external control magnetic field to the area of said drive layer intermediate said first and second electrodes; a magnetically responsive domain detecting means mounted in magnetically coupled relationship with said channel of said magnetic layer so as to effect an electrical impulse in response to movement of a magnetic domain in said channel upon passing said detector; a voltage responsive input signal being responsive to the voltage component of an electrical power quantity to be measured and connected across said first and second electrodes so as to establish an electric field in said drive layer in response to the instantaneous magnitude of said voltage component such that a substantially uniform current density is established in said drive layer between said first and second electrodes and adjacent said channel; a current responsive input signal responsive to the current component of the power quantity to be measured by said apparatus and connected to said magnetic field source so as to control said external control magnetic field in response to the instantaneous magnitude of said current component and to orient said uniform current density in response thereto whereby said magnetic domain is propagated at a velocity proportional to the product of the voltage and current power components and the number of impulses generated by said detector is proportional to watthours of electric energy of the measured electrical power.

Claim 23

The watthour metering apparatus as claimed in claim 19 wherein said magnetic field source includes a current coil.

Claim 24

The watthour metering apparatus as claimed in claim 20 wherein said means for providing a circular domain channel includes a permanent magnet having an annular groove facing said magnetic layer.