A magnetoresistance effect element and a Heusler alloy in which a state change due to annealing does not easily occur. The element includes a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy in which a portion of elements of an alloy represented by Co.sub.2Fe.sub.αZ.sub.β is substituted with a substitution element, in which Z is one or more elements selected from the group consisting of Al, Si, Ga, Ge, and Sn, α and β satisfy 2.3≤α+β, α<β, and 0.5<α<1.9, and the substitution element is one or more elements selected from the group consisting of elements having a melting point higher than that of Fe among elements of Groups 4 to 10.

A magnetic sensor system includes two magnetic sensors that detect components in two directions of an external magnetic field, an additional magnetic field generation section, and a signal processing circuit. The additional magnetic field generation section is capable of generating two additional magnetic fields for use in measuring the sensitivities of the two magnetic sensors. The signal processing circuit includes a sensitivity measurement processing section and a detection signal correction processing section. The sensitivity measurement processing section measures the sensitivities based on data concerning changes in the detection signals of the two magnetic sensors when the additional magnetic field generation section is controlled to generate two additional magnetic fields. The detection signal correction processing section performs processing for reducing change components attributable to the two additional magnetic fields on the detection signals of the two magnetic sensors.

A magnetic sensor system includes two magnetic sensors that detect components in two directions of an external magnetic field, an additional magnetic field generation section, and a signal processing circuit. The additional magnetic field generation section is capable of generating two additional magnetic fields for use in measuring the sensitivities of the two magnetic sensors. The signal processing circuit includes a sensitivity measurement processing section and a detection signal correction processing section. The sensitivity measurement processing section measures the sensitivities based on data concerning changes in the detection signals of the two magnetic sensors when the additional magnetic field generation section is controlled to generate two additional magnetic fields. The detection signal correction processing section performs processing for reducing change components attributable to the two additional magnetic fields on the detection signals of the two magnetic sensors.

A current sensing system, comprising at least one magnetic tunnel junction device placed adjacent to a current carrying conductor electrically connected to a battery of a vehicle. The magnetic tunnel junction device is configured to measure a magnetic field around the conductor. A monitoring device is operatively connected to the magnetic tunnel junction device, wherein the monitoring device is configured to receive the magnetic field measurement and determine an estimate of the current flowing through the conductor.

An impedance measurement system for detecting an analyte in a sample is disclosed. The system includes first, second, and third electrodes, wherein at least a portion of the third electrode is positioned between the first and second electrodes, means for generating an electromagnetic field between the first and second electrodes, means for electrically controlling the third electrode, wherein the third electrode modifies the electromagnetic field, and a processor for detecting a presence of the analyte in the sample, based at least in part on a property of the electromagnetic field.

A Hall element that exhibits an anomalous Hall effect includes a substrate and a thin film as a magneto-sensitive layer on the substrate, the thin film having a composition of Fe.sub.xSn.sub.1-x, where 0.5≤x<0.9. The thin film may be made of an alloy of Fe and Sn, and a dopant element. The dopant element may be a transition metal element that modulates spin-orbit coupling or magnetism. The dopant element may be a main-group element that has a different number of valence electrons from Sn and modulates carrier density. The dopant element may be a main-group element that modulates density of states.

A light detection element includes: a plurality of magnetic elements, wherein each of the magnetic elements includes a first ferromagnetic layer that is irradiated with light and a second ferromagnetic layer and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and wherein at least two of the magnetic elements are arranged to be inside a spot of the light applied to the first ferromagnetic layers of the at least two of the magnetic elements.

A method for determining authenticity of a security device of a component in an imaging device includes receiving, by the security device, an authentication challenge including one or more commands and executing, by the security device, the one or more commands in response to receiving the authentication challenge. A magnetic field profile is generated based on current drawn by the security device from a power source while the security device is executing the one or more commands, the generated magnetic field profile indicating an authentication response of the security device to the authentication challenge for use in determining authenticity of the security device.

A method for determining authenticity of a security device of a component in an imaging device includes receiving, by the security device, an authentication challenge including one or more commands and executing, by the security device, the one or more commands in response to receiving the authentication challenge. A magnetic field profile is generated based on current drawn by the security device from a power source while the security device is executing the one or more commands, the generated magnetic field profile indicating an authentication response of the security device to the authentication challenge for use in determining authenticity of the security device.

A magnetoresistive Z-axis gradient sensor chip, which is used to detect the gradient in the XY plane of a Z-axis magnetic field component generated by a magnetic medium; the sensor chip comprises a Si substrate, a collection of two or two groups of flux guide devices separated a distance Lg and an arrangement of electrically interconnected magnetoresistive sensor units. The magnetoresistive sensor units are located on the Si substrate and located above or below the edge of the flux guide devices as well; the flux guide devices convert the component of the Z-axis magnetic field into the direction parallel to the surface of the Si substrate along the sensing axis direction of the magnetoresistive sensing units. The magnetoresistive sensor units are electrically interconnected into a half bridge or a full bridge gradiometer arrangement, wherein the opposite bridge arms are separated by distance Lg. This sensor chip can be utilized with a PCB or in combination with a PCB plus back-bias magnet with casing. The sensor measures the Z-axis magnetic field gradient by using magnetoresistive sensors with in-plane sensing axes. This sensor chip has several advantages relative to a Hall Effect sensor device, including smaller size, lower power consumption, and higher magnetic field sensitivity.