Abstract: A MLU-based magnetic device including a plurality of MLU-based magnetic cells, each MLU cell including a first ferromagnetic layer having a first magnetization, a second ferromagnetic layer having a second magnetization, and a spacing layer between the first and second ferromagnetic layers. An input device is configured for generating an input signal adapted for changing the orientation of the first magnetization relative to the second magnetization and vary a resistance of the MLU device. A bit line is configured for passing a sense signal adapted for measuring the resistance. A processing unit is configured for computing an electrical variation from the sense signal and outputting an electrical variation signature. The present disclosure further pertains to an authentication method for reading the MLU device.

Abstract: An apparatus for generating a magnetic field including permanent magnets arranged in a plane, each magnet being spatially separated along the plane from the adjacent magnet by a predetermined spacing, each magnet having a magnetic polarity opposed to the polarity of the adjacent magnet such that a magnetic field of adjacent magnets is oriented substantially perpendicular to the plane and in opposite directions, each magnet being spatially separated in the plane from the adjacent magnet by a nonmagnetic material. A method for programming a magnetic device or sensor device using the apparatus is also described.

Abstract: A MLU-based magnetic device including a plurality of MLU-based magnetic cells, each MLU cell including a first ferromagnetic layer having a first magnetization, a second ferromagnetic layer having a second magnetization, and a spacing layer between the first and second ferromagnetic layers. An input device is configured for generating an input signal adapted for changing the orientation of the first magnetization relative to the second magnetization and vary a resistance of the MLU device. A bit line is configured for passing a sense signal adapted for measuring the resistance. A processing unit is configured for computing an electrical variation from the sense signal and outputting an electrical variation signature. The present disclosure further pertains to an authentication method for reading the MLU device.

Abstract: An apparatus for generating a magnetic field including permanent magnets arranged in a plane, each magnet being spatially separated along the plane from the adjacent magnet by a predetermined spacing, each magnet having a magnetic polarity opposed to the polarity of the adjacent magnet such that a magnetic field of adjacent magnets is oriented substantially perpendicular to the plane and in opposite directions, each magnet being spatially separated in the plane from the adjacent magnet by a nonmagnetic material. A method for programming a magnetic device or sensor device using the apparatus is also described.

Abstract: A magnetoresistive-based signal shaping circuit for audio applications includes: a field emitting device configured for receiving an input current signal from an audio signal source and for generating a magnetic field in accordance with the input current signal, and a first magnetoresistive element having a first electrical resistance and electrically connected in series to a second magnetoresistive element having a second electrical resistance. The magnetoresistive-based signal shaping device provides an output signal across the second magnetoresistive element when an input voltage is applied across the first and second magnetoresistive element in series. The output signal is a function of the electrical resistance and yields a dynamic range compression effect. The first and second electrical resistance vary with the magnetic field in an opposite fashion.

Abstract: A magnetoresistive-based signal shaping circuit for audio applications includes: a field emitting device configured for receiving an input current signal from an audio signal source and for generating a magnetic field in accordance with the input current signal, and a first magnetoresistive element having a first electrical resistance and electrically connected in series to a second magnetoresistive element having a second electrical resistance. The magnetoresistive-based signal shaping device provides an output signal across the second magnetoresistive element when an input voltage is applied across the first and second magnetoresistive element in series. The output signal is a function of the electrical resistance and yields a dynamic range compression effect. The first and second electrical resistance vary with the magnetic field in an opposite fashion.

Abstract: A programmable magnetic device for generating random numbers during a programming operation, including an array of a plurality of magnetic tunnel junctions. Each magnetic tunnel junction includes a reference layer having a reference magnetization; a tunnel barrier layer; and a storage layer having a storage magnetization. The programmable magnetic device is arranged such that, during the programming operation, the storage magnetization is orientable in an unstable magnetization configuration and relaxable randomly in one of a plurality of stable or metastable configurations from the unstable magnetization configuration.

Abstract: A magnetic device configured to perform an analog adder circuit function and including a plurality of magnetic units. Each magnetic unit includes n magnetic tunnel junctions electrically connected in series via a current line. Each magnetic tunnel junction includes a storage magnetic layer having a storage magnetization, a sense magnetic layer having a sense magnetization, and a tunnel barrier layer. Each magnetic unit also includes n input lines, each being configured to generate a magnetic field adapted for varying a direction of the sense magnetization and a resistance of the n magnetic tunnel junctions, based on an input. Each of the n magnetic units is configured to add said n inputs to generate an output signal that varies in response to the n resistances.

Abstract: A programmable magnetic device for generating random numbers during a programming operation, including an array of a plurality of magnetic tunnel junctions. Each magnetic tunnel junction includes a reference layer having a reference magnetization; a tunnel barrier layer; and a storage layer having a storage magnetization. The programmable magnetic device is arranged such that, during the programming operation, the storage magnetization is orientable in an unstable magnetization configuration and relaxable randomly in one of a plurality of stable or metastable configurations from the unstable magnetization configuration.

Abstract: A magnetic memory device including a plurality of magnetic units, each unit including a first and second magnetic tunnel junctions—electrically connected in series by a current line and a strap. Each junction includes a first and second storage layer having a first and second storage magnetization and a first sense magnetic layer having a first and second senses magnetization. A field line is configured to provide an input signal generating a first and second magnetic field for varying the first and second sense magnetization. Each magnetic unit is provided with a data state such that the first and second storage magnetizations are aligned in opposed directions. The first and second magnetic field are adapted for varying respectively the first and second sense magnetization in a first and second direction opposed to the first direction.

Abstract: A magnetic memory device including a plurality of magnetic units, each unit including a first and second magnetic tunnel junctions-electrically connected in series by a current line and a strap. Each junction includes a first and second storage layer having a first and second storage magnetization and a first sense magnetic layer having a first and second senses magnetization. A field line is configured to provide an input signal generating a first and second magnetic field for varying the first and second sense magnetization. Each magnetic unit is provided with a data state such that the first and second storage magnetizations are aligned in opposed directions. The first and second magnetic field are adapted for varying respectively the first and second sense magnetization in a first and second direction opposed to the first direction.

Abstract: A magnetic device configured to perform an analog adder circuit function and including a plurality of magnetic units. Each magnetic unit includes n magnetic tunnel junctions electrically connected in series via a current line. Each magnetic tunnel junction includes a storage magnetic layer having a storage magnetization, a sense magnetic layer having a sense magnetization, and a tunnel barrier layer. Each magnetic unit also includes n input lines, each being configured to generate a magnetic field adapted for varying a direction of the sense magnetization and a resistance of the n magnetic tunnel junctions, based on an input. Each of the n magnetic units is configured to add said n inputs to generate an output signal that varies in response to the n resistances.

Abstract: A multibit MRAM cell including a magnetic tunnel junction including a sense layer having a freely orientable sense magnetization; a tunnel barrier layer; and a synthetic antiferromagnet storage layer having a first and second storage layer. The sense magnetization induces a dipolar field having a magnitude above a spin-flop field of the storage layer. The MRAM cell also includes aligning means for aligning the sense magnetization in a plurality of distinct orientations such as to encode a plurality of distinct logic states in the MRAM cell. The present disclosure also concerns a method for operating the multibit MRAM cell.

Abstract: A self-referenced MRAM cell including a reference layer having a fixed reference magnetization, a sense layer having a free sense magnetization, a tunnel barrier, a biasing layer having bias magnetization and a biasing antiferromagnetic layer pinning the bias magnetization in a bias direction when MRAM cell is at temperature equal or below a bias threshold temperature. The bias magnetization is arranged for inducing a bias field adapted for biasing the sense magnetization in a direction opposed to the bias direction, such that the biased sense magnetization varies linearly in the presence of the external magnetic field, when the external magnetic field is oriented in a direction substantially perpendicular to the one of the reference magnetization. The present disclosure further concerns a magnetic field sensor including a plurality of the self-referenced MRAM cell and a method for programming the magnetic field sensor.

Abstract: A method for writing a MRAM device, including magnetic tunnel junction with a storage layer, a sense layer, and a spacer layer between the storage and sense layers. At least one of the storage and sense layers has a magnetic anisotropy axis. The method includes an initialization step including: applying an initial heating current pulse for heating the magnetic tunnel junction to a temperature above a threshold temperature at which a storage magnetization is freely orientable, providing an initial resultant magnetic field for adjusting the storage magnetization in an initial direction oriented along the magnetic anisotropy axis. The method allows performing the writing step with improved reproducibly.

Abstract: A multi-bit magnetic random access memory (MRAM) cell including a magnetic tunnel junction including: a first magnetic storage layer, a second magnetic storage layer, a magnetic sense layer, a first spacer layer between the first magnetic storage layer and the magnetic sense layer, and a second spacer layer between the second magnetic storage layer and the sense layer. The first and second storage magnetization are switchable between m directions to store data corresponding to one of m2 logic states, with m>2. The present disclosure further concerns a method for writing and reading to the MRAM cell and to memory devices including multi-bit MRAM cells.

Abstract: A self-referenced MRAM cell including a reference layer having a fixed reference magnetization, a sense layer having a free sense magnetization, a tunnel barrier, a biasing layer having bias magnetization and a biasing antiferromagnetic layer pinning the bias magnetization in a bias direction when MRAM cell is at temperature equal or below a bias threshold temperature. The bias magnetization is arranged for inducing a bias field adapted for biasing the sense magnetization in a direction opposed to the bias direction, such that the biased sense magnetization varies linearly in the presence of the external magnetic field, when the external magnetic field is oriented in a direction substantially perpendicular to the one of the reference magnetization. The present disclosure further concerns a magnetic field sensor including a plurality of the self-referenced MRAM cell and a method for programming the magnetic field sensor.

Abstract: A method for writing a MRAM device, including magnetic tunnel junction with a storage layer, a sense layer, and a spacer layer between the storage and sense layers. At least one of the storage and sense layers has a magnetic anisotropy axis. The method includes an initialization step including: applying an initial heating current pulse for heating the magnetic tunnel junction to a temperature above a threshold temperature at which a storage magnetization is freely orientable, providing an initial resultant magnetic field for adjusting the storage magnetization in an initial direction oriented along the magnetic anisotropy axis. The method allows performing the writing step with improved reproducibly.

Abstract: A multibit MRAM cell including a magnetic tunnel junction including a sense layer having a freely orientable sense magnetization; a tunnel barrier layer; and a synthetic antiferromagnet storage layer having a first and second storage layer. The sense magnetization induces a dipolar field having a magnitude above a spin-flop field of the storage layer. The MRAM cell also includes aligning means for aligning the sense magnetization in a plurality of distinct orientations such as to encode a plurality of distinct logic states in the MRAM cell. The present disclosure also concerns a method for operating the multibit MRAM cell.

Abstract: Self-referenced magnetic random access memory (MRAM) cell including a magnetic tunnel junction including a sense layer; a storage layer having a storage magnetization; a tunnel barrier layer between the sense and the storage layers; and an antiferromagnetic layer exchange-coupling the storage layer such that the storage magnetization can be pinned when the antiferromagnetic layer is below a critical temperature and freely varied when the antiferromagnetic layer is heated at or above the critical temperature. The sense layer includes a first sense layer having a first sense magnetization, a second sense layer having a second sense magnetization and spacer layer between the first and second sense layers. The MRAM cell can be read with low power consumption.