Magnetic sensors and magnetic measurement methods

Abstract

[Objective] The objective is to provide a magnetic sensor and a magnetic measurement method capable of measuring small magnetic fields with high precision. [Solution] A magnetic sensor (1) includes: a variable magnetic field detection unit (100a); the variable magnetic field detection unit (100a) includes: a magnetoresistive element (10a) having a first layer (13) that can be magnetized along the direction of the measured magnetic field, a second layer (11) that can maintain the magnetization direction in the first direction (X direction), and a non-magnetic layer (12) located between the first layer (13) and the second layer (11), and a magnetization control unit (20) that reversibly reverses the magnetization (11m) orientation of the second layer (11); wherein the magnetization control unit (20) may be an energized magnetization control unit (201) whose magnetization direction is reversed by energization, or may have a spin Hall layer (21) and an anisotropic variable layer (22). The magnetization control unit (20) has a spin Hall layer (21). The second layer (11) can be a variable second layer (111) or the second layer (11) can be integrated with the magnetization control unit (20) to be an electrically variable second layer (112).

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