Abstract: A planar Hall effect (PHE) sensor for measuring at an external magnetic field includes a plurality of elongated magnetic regions. Each magnetic region includes a ferromagnetic material that is magnetized along a longitudinal axis. The magnetic regions cross one another at an overlap region that is characterized by a plurality of easy magnetic axes. At least two pairs of electrical leads are each aligned along one of the easy magnetic axes. A current source may be connected to a first pair of the electrical leads to cause a current to flow through the overlap region along a first easy magnetic axis. A voltage measurement device may be connected to another pair of the electrical leads to measure a PHE voltage that is generated by a component of the external magnetic field that is perpendicular to the easy magnetic axis along which the overlap region is magnetized.

Abstract: A planar Hall effect (PHE) sensor for measuring at an external magnetic field includes a plurality of elongated magnetic regions. Each magnetic region includes a ferromagnetic material that is magnetized along a longitudinal axis. The magnetic regions cross one another at an overlap region that is characterized by a plurality of easy magnetic axes. At least two pairs of electrical leads are each aligned along one of the easy magnetic axes. A current source may be connected to a first pair of the electrical leads to cause a current to flow through the overlap region along a first easy magnetic axis. A voltage measurement device may be connected to another pair of the electrical leads to measure a PHE voltage that is generated by a component of the external magnetic field that is perpendicular to the easy magnetic axis along which the overlap region is magnetized.

Abstract: A multi-state MRAM device comprises N overlapping ovals defining a free ferromagnetic region. The size of the free ferromagnetic region is controlled the shape anisotropy of the configuration via at least a aspect ratio greater than 2, of the free ferromagnetic region. The free ferromagnetic region has a magnetic moment spontaneously aligned along the long axis in each oval outside the center region. A center magnetic moment has a multitude of exactly 2*N stable orientations determined by the magnetic moments in the segments of the ovals outside the center region. An embodiment is an MRAM device using tunneling junctions to achieve a multi-state memory configuration. Certain embodiments includes an electrically conducting heavy-metal layer disposed adjacent to and connected with the free ferromagnetic region. Some embodiments include a topological insulating material, such as Bi2Se3.

Abstract: A multi-state MRAM device comprises N overlapping ovals defining a free ferromagnetic region. The size of the free ferromagnetic region is controlled the shape anisotropy of the configuration via at least a aspect ratio greater than 2, of the free ferromagnetic region. The free ferromagnetic region has a magnetic moment spontaneously aligned along the long axis in each oval outside the center region. A center magnetic moment has a multitude of exactly 2*N stable orientations determined by the magnetic moments in the segments of the ovals outside the center region. An embodiment is an MRAM device using tunneling junctions to achieve a multi-state memory configuration. Certain embodiments includes an electrically conducting heavy-metal layer disposed adjacent to and connected with the free ferromagnetic region. Some embodiments include a topological insulating material, such as Bi2Se3.

Abstract: The present invention discloses plural planar Hall-effect sensors each having a magnetic sensing region of an elongated shape, the magnetic sensing regions having plural orientations, wherein, for a ratio of long axis length to short axis length greater than a predetermined number, effective single magnetic domain behavior is exhibited in the sensing region, the sensing having shape-induced uniaxial magnetic anisotropy with the easy axis parallel to the long axis of the magnetic sensing region; further wherein the magnitude of the uniaxial magnetic anisotropy depends on the ratio of the thickness of the sensing region to the length of the short axis, and method of operating the same to measure plural magnetic field components.

Abstract: The present invention discloses a planar Hall-effect sensor with a magnetic sensing region of an elongated shape, wherein, for a ratio of long axis length to short axis length greater than a predetermined number, effective single magnetic domain behavior is exhibited in the sensing region, the sensing having shape-induced uniaxial magnetic anisotropy with the easy axis parallel to the long axis of the magnetic sensing region; further wherein the magnitude of the uniaxial magnetic anisotropy depends on the ratio of the thickness of the sensing region to the length of the short axis.