Magnetic logic unit (MLU) cell and amplifier having a linear magnetic signal

Patent metadata

Field	Value
Publication number	US-9583695-B2
Application number	US-201314431125-A
Country	US
Kind code	B2
Filing date	Sep 12, 2013
Priority date	Sep 25, 2012
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A magnetic logic unit (MLU) cell includes a first magnetic tunnel junction and a second magnetic tunnel junction, each magnetic tunnel junction including a first magnetic layer having a first magnetization, a second magnetic layer having a second magnetization, and a tunnel barrier layer between the first and second layer. A field line for passing a field current such as to generate an external magnetic field is adapted to switch the first magnetization. The first magnetic layer is arranged such that the magnetic tunnel junction magnetization varies linearly with the generated external magnetic field. An MLU amplifier includes a plurality of the MLU cells. The MLU amplifier has large gains, extended cut off frequencies and improved linearity.

First claim

The invention claimed is:

1. Magnetic logic unit (MLU) cell comprising:
a first magnetic tunnel junction and a second magnetic tunnel junction, each magnetic tunnel junction comprising a first magnetic layer having a first magnetization, a second magnetic layer having a second magnetization that is reversible at a high temperature threshold and pinned at a low temperature threshold, and a tunnel barrier layer between the first magnetic layer and second magnetic layer;
a strap, electrically connecting one end of the first magnetic tunnel junction in series with one end of the second magnetic tunnel junction; and
a field line for passing a field current that generates an external magnetic field adapted to switch the first magnetization;
the first magnetic layer being arranged such that the first magnetization varies linearly with the generated external magnetic field.

2. The MLU cell according to claim 1 , wherein the first magnetization of the first magnetic layer comprises an anisotropy that is substantially perpendicular to the second magnetization and substantially parallel to the field line.

3. The MLU cell according to claim 2 , wherein the first magnetic layer comprises an elliptical shape with its long axis being substantially perpendicular to the second magnetization and substantially parallel to the field line.

4. The MLU cell according to claim 2 , wherein the first magnetic layer has a uniaxial magnetocrystalline anisotropy being substantially perpendicular to the storage magnetization and substantially parallel to the field line.

5. The MLU cell according to claim 2 , further comprising a biasing field adapted to orient the first magnetization substantially perpendicular to the second magnetization and substantially parallel to the field line.

6. The MLU cell according to claim 5 , further comprising a permanent magnet for generating the biasing field.

7. The MLU cell according to claim 1 , wherein the first magnetic layer is arranged such as to comprise a vortex configuration with a vortex center and wherein the vortex center can move substantially perpendicular to the external magnetic field when the external magnetic field is applied.

8. The MLU cell according to claim 1 , wherein the first magnetic layer comprises a synthetic antiferromagnet sense layer, and the field line is arranged for applying the external magnetic field substantially parallel to the anisotropy axis of the first magnetic layer when the field current is passed, and wherein the first magnetic layer is further configured such that the magnetization response curve has a linear portion when the external magnetic field is applied between a spin-flop value and a saturation magnetic field.

9. MLU amplifier comprising a plurality of MLU cells, each MLU cell comprising: a first magnetic tunnel junction and a second magnetic tunnel junction, each magnetic tunnel junction comprising a first magnetic layer having a first magnetization, a second magnetic layer having a second magnetization that is reversible at a high temperature threshold and pinned at a low temperature threshold, and a tunnel barrier layer between the first magnetic layer and second magnetic layer; a strap, electrically connecting one end of the first magnetic tunnel junction in series with one end of the second magnetic tunnel junction; and a field line for passing a field current that generates an external magnetic field adapted to switch the first magnetization; the first magnetic layer being arranged such that the first magnetization varies linearly with the generated external magnetic field;
wherein the MLU cells are electrically connected in series via a current line.

Assignees

• Crocus Technology Sa

Inventors

• Prejbeanu Ioan Lucian
• Dieny Bernard
• Mackay Kenneth
• Cambou Bertrand

Classifications

• H03F15/00 Primary

  Amplifiers using galvano-magnetic effects not involving mechanical movement, e.g. using Hall effect · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title

• G11C11/16

  using elements in which the storage effect is based on magnetic spin effect · CPC title

• H01L43/02 Primary

  Electricity · mapped topic

• H03K19/18

  using galvano-magnetic devices, e.g. Hall-effect devices · CPC title