Abstract: The present disclosure concerns a magnetic random access memory MRAM cell comprising a tunnel magnetic junction formed from a first ferromagnetic layer, a second ferromagnetic layer having a second magnetization that can be oriented relative to an anisotropy axis of the second ferromagnetic layer at a predetermined high temperature threshold, and a tunnel barrier; a first current line extending along a first direction and in communication with the magnetic tunnel junction; the first current line being configured to provide an magnetic field for orienting the second magnetization when carrying a field current; wherein the MRAM cell is configured with respect to the first current line such that when providing the magnetic field, at least a component of the magnetic field is substantially perpendicular to said anisotropy axis. The MRAM cell has an improved switching efficiency, lower power consumption and improved dispersion of the switching field compared to conventional MRAM cells.

Abstract: The present disclosure concerns a self-referenced magnetic random access memory-based ternary content addressable memory (MRAM-based TCAM) cell comprising a first and second magnetic tunnel junction; a first and second conducting strap adapted to pass a heating current in the first and second magnetic tunnel junction, respectively; a conductive line electrically connecting the first and second magnetic tunnel junctions in series; a first current line for passing a first field current to selectively write a first write data to the first magnetic tunnel junction; and a second current line for passing a write current to selectively write a second write data to the second magnetic tunnel junction, such that three distinct cell logic states can be written in the MRAM-based TCAM cell.

Abstract: The present disclosure concerns a self-referenced MRAM element, comprising a magnetic tunnel junction having a magnetoresistance, comprising: a storage layer having a storage magnetization that is pinned along a first direction when the magnetic tunnel junction is at a low temperature threshold; a sense layer having a sense magnetization; and a tunnel barrier layer included between the storage layer and the sense layer; and an aligning device arranged for providing the sense magnetization with a magnetic anisotropy along a second direction that is substantially perpendicular to the first direction such that the sense magnetization is adjusted about the second direction; the aligning device being further arranged such that, when a first read magnetic field is provided, a resistance variation range of the magnetic tunnel junction is at least about 20% of the magnetoresistance. The self-referenced MRAM cell can be read with an increased reliability and has reducing power consumption.

Abstract: Method for writing and reading more than two data bits to a MRAM cell comprising a magnetic tunnel junction formed from a read magnetic layer having a read magnetization, and a storage layer comprising a first storage ferromagnetic layer having a first storage magnetization, a second storage ferromagnetic layer having a second storage magnetization; the method comprising: heating the magnetic tunnel junction above a high temperature threshold; and orienting the first storage magnetization at an angle with respect to the second storage magnetization such that the magnetic tunnel junction reaches a resistance state level determined by the orientation of the first storage magnetization relative to that of the read magnetization. The method allows for storing at least four distinct state levels in the MRAM cell using only one current line to generate a writing field.

Abstract: The present disclosure concerns a method for writing to a MRAM cell comprising a magnetic tunnel junction formed from a storage layer having a storage magnetization; a reference layer having a reference magnetization; and a tunnel barrier layer included between the sense and storage layers; and a current line electrically connected to said magnetic tunnel junction; the method comprising: passing a heating current in the magnetic tunnel junction for heating the magnetic tunnel junction; passing a field current for switching the storage magnetization in a written direction in accordance with the polarity of the field current. The magnitude of the heating current is such that it acts as a spin polarized current and can adjust the storage magnetization; and the polarity of the heating current is such as to adjust the storage magnetization substantially towards said written direction.

Abstract: A magnetic random access memory (MRAM) cell includes a storage layer, a sense layer, and a spacer layer between the storage layer and the sense layer. A field line is magnetically coupled to the MRAM cell to induce a magnetic field along a magnetic field axis, and at least one of the storage layer and the sense layer has a magnetic anisotropy axis that is tilted relative to the magnetic field axis. During a write operation, a storage magnetization direction is switchable between m directions to store data corresponding to one of m logic states, with m>2, where at least one of the m directions is aligned relative to the magnetic anisotropy axis, and at least another one of the m directions is aligned relative to the magnetic field axis. During a read operation, a sense magnetization direction is varied, relative to the storage magnetization direction, to determine the data stored by the storage layer.

Abstract: The present disclosure concerns a method for writing to a self-referenced MRAM cell comprising a magnetic tunnel junction comprising: a storage layer including a first ferromagnetic layer having a first storage magnetization, a second ferromagnetic layer having a second storage magnetization, and a non-magnetic coupling layer separating the first and second ferromagnetic layers; a sense layer having a free sense magnetization; and a tunnel barrier layer included between the sense and storage layers; the first and second ferromagnetic layers being arranged such that a dipolar coupling between the storage) and the sense layers is substantially null; the method comprising: switching the second ferromagnetic magnetization by passing a spin-polarized current in the magnetic tunnel junction; wherein the spin-polarized current is polarized when passing in the sense layer, in accordance with the direction of the sense magnetization. The MRAM cell can be written with low power consumption.

Abstract: A magnetic random access memory cell includes a sense layer, a storage layer, and a spacer layer disposed between the sense layer and the storage layer. During a write operation, the storage layer has a magnetization direction that is switchable between m directions to store data corresponding to one of m logic states, with m>2. During a read operation, the sense layer has a magnetization direction that is varied, relative to the magnetization direction of the storage layer, to determine the data stored by the storage layer.

Abstract: The present disclosure concerns a MRAM element comprising a magnetic tunnel junction comprising: a storage layer, a sense layer, and a tunnel barrier layer included between the storage layer and the sense layer; the storage layer comprising a first magnetic layer having a first storage magnetization; a second magnetic layer having a second storage magnetization; and a non-magnetic coupling layer separating the first and second magnetic layers such that the first storage magnetization is substantially antiparallel to the second storage magnetization; the first and second magnetic layers being arranged such that: at a read temperature the first storage magnetization is substantially equal to the second storage magnetization; and at a write temperature which is higher than the read temperature the second storage magnetization is larger than the first storage magnetization. The disclosed MRAM element generates a low stray field when the magnetic tunnel junction is cooled at a low temperature.

Abstract: Magnetic random access memory (MRAM) element suitable for a thermally-assisted write operation and for a self-referenced read operation, comprising a magnetic tunnel junction portion having a first portion and a second portion, each portion comprising a storage layer, a sense layer, and a tunnel barrier layer; the magnetic tunnel junction further comprising an antiferromagnetic layer between the two storage layers and pinning a storage magnetization of each of the storage layers below a critical temperature, and freeing them at and above the critical temperature; such that, during a write operation, a free magnetization of each of the sense layer is magnetically saturable according to a direction of a write magnetic field when applied; and the storage magnetizations are switchable in a direction substantially parallel and corresponding to the direction of the saturated free magnetizations.

Abstract: A method of writing in a memory device comprising a plurality of MRAM cells, each cell including a magnetic tunnel junction having a resistance that can be varied during a write operation when heated at a high threshold temperature; a plurality of word lines connecting cells along a row; and a plurality of bit lines connecting cells along a column; the method comprising supplying a bit line voltage to one of the bit lines and a word line voltage to one of the word lines for passing a heating current through the magnetic tunnel junction of a selected cell; said word line voltage is a word line overdrive voltage being higher than the core operating voltage of the cells such that the heating current has a magnitude that is high enough for heating the magnetic tunnel junction at the predetermined high threshold temperature. The memory device can be written with low power consumption.

Abstract: A memory device includes a plurality of magnetic random access memory (MRAM) cells, a field line, and a field line controller configured to generate a write sequence that traverses the field line. The write sequence is for writing a multi-bit word to the plurality of MRAM cells. The multi-bit word includes a first subset of bits having a first polarity and a second subset of bits having a second polarity. The write sequence writes concurrently to at least a subset of the plurality of MRAM cells corresponding to the first subset of bits having the first polarity, then subsequently writes concurrently to a remaining subset of the plurality of MRAM cells corresponding to the second subset of bits having the second polarity.

Abstract: MRAM cell comprising a magnetic tunnel junction comprising a storage layer having a net storage magnetization being adjustable when the magnetic tunnel junction is at a high temperature threshold and being pinned at a low temperature threshold; a sense layer having a reversible sense magnetization; and a tunnel barrier layer between the sense and storage layers; at least one of the storage and sense layer comprising a ferrimagnetic 3d-4f amorphous alloy material comprising a sub-lattice of 3d transition metals atoms providing a first magnetization and a sub-lattice of 4f rare-earth atoms providing a second magnetization, such that at a compensation temperature of said at least one of the storage layer and the sense layer, the first magnetization and the second magnetization are substantially equal. The disclosed MRAM cell can be written and read using a small writing and reading field, respectively.

Abstract: The present disclosure concerns a magnetic element to be written using a thermally-assisted switching write operation comprising a magnetic tunnel junction formed from a tunnel barrier being disposed between first and second magnetic layers, said second magnetic layer having a second magnetization which direction can be adjusted during a write operation when the magnetic tunnel junction is heated at a high threshold temperature; an upper current line connected at the upper end of the magnetic tunnel junction; and a strap portion extending laterally and connected to the bottom end of the magnetic tunnel junction; the magnetic device further comprising a bottom thermal insulating layer extending substantially parallel to the strap portion and arranged such that the strap portion is between the magnetic tunnel junction and the bottom thermal insulating layer. The magnetic element allows for reducing heat losses during the write operation and has reduced power consumption.

Abstract: The present disclosure concerns a magnetic random access memory (MRAM) cell comprising a magnetic tunnel junction comprising a synthetic storage layer; a sense layer having a sense magnetization that is reversible; and a tunnel barrier layer between the sense layer and the storage layer; wherein a net local magnetic stray field couples the storage layer with the sense layer; and wherein the net local magnetic stray field being such that the net local magnetic stray field coupling the sense layer is below 50 Oe. The disclosure also pertains to a method for writing and reading the MRAM cell. The disclosed MRAM cell can be written and read with lower consumption in comparison to conventional MRAM cells.

Abstract: A magnetic random access memory (MRAM) cell with a thermally assisted switching (TAS) writing procedure, comprising a magnetic tunnel junction formed from a ferromagnetic storage layer having a first magnetization adjustable at a high temperature threshold, a ferromagnetic reference layer having a fixed second magnetization direction, and an insulating layer, said insulating layer being disposed between the ferromagnetic storage and reference layers; a select transistor being electrically connected to said magnetic tunnel junction and controllable via a word line; a current line electrically connected to said magnetic tunnel junction; characterized in that the magnetocrystalline anisotropy of the ferromagnetic storage layer is essentially orthogonal with the magnetocrystalline anisotropy of the ferromagnetic reference layer. The TAS-MRAM cell of the invention can be written with a smaller magnetic field than the one used in conventional TAS-MRAM cells and has low power consumption.

Abstract: A magnetic random access memory (MRAM) cell with a thermally assisted switching (TAS) writing procedure, comprising a magnetic tunnel junction formed from a ferromagnetic storage layer having a first magnetization adjustable at a high temperature threshold, a ferromagnetic reference layer having a fixed second magnetization, and an insulating layer, said insulating layer being disposed between the ferromagnetic storage and reference layers; a select transistor being electrically connected to said magnetic tunnel junction and controllable via a word line; a current line, electrically connected to said magnetic tunnel junction, passing at least a write current; characterized in that the magnetocrystalline anisotropy of the ferromagnetic storage layer is substantially orthogonal with the magnetocrystalline anisotropy of the ferromagnetic reference layer. The STT-based TAS-MRAM cell achieves simultaneously thermal stability and requires low write current density.

Abstract: A memory device includes a first plurality of magnetic random access memory (MRAM) cells positioned along a first direction, and a first bit line electrically connected to the first plurality of MRAM cells, the bit line oriented in the first direction. The device includes a first plurality of field lines oriented in a second direction different from the first direction, the first plurality of field lines being spaced such that only a corresponding first one of the first plurality of MRAM cells is configurable by each of the first plurality of field lines. The device includes a second plurality of field lines oriented in a third direction different from the first direction and the second direction, the second plurality of field lines being spaced such that only a corresponding second one of the first plurality of MRAM cells is configurable by each of the second plurality of field lines.

Abstract: According to the present invention there is provided a method of counter-measuring against side channel attacks, the method comprising executing a block-cipher algorithm to mask intermediate variables, wherein the block-cipher algorithm comprises one or more non-linear functions, characterised in that at least one of the non-linear functions is implemented using a match-in-place function.

Abstract: The present disclosure concerns a magnetic random access memory MRAM cell comprising a tunnel magnetic junction formed from a first ferromagnetic layer, a second ferromagnetic layer having a second magnetization that can be oriented relative to an anisotropy axis of the second ferromagnetic layer at a predetermined high temperature threshold, and a tunnel barrier; a first current line extending along a first direction and in communication with the magnetic tunnel junction; the first current line being configured to provide an magnetic field for orienting the second magnetization when carrying a field current; wherein the MRAM cell is configured with respect to the first current line such that when providing the magnetic field, at least a component of the magnetic field is substantially perpendicular to said anisotropy axis. The MRAM cell has an improved switching efficiency, lower power consumption and improved dispersion of the switching field compared to conventional MRAM cells.