High-precision composite magnetic gradiometer based on superconductivity and tunneling magnetoresistance

Abstract

The invention discloses a high-precision composite magnetic gradiometer based on superconductivity and tunneling magnetoresistance. The gradiometer sequentially comprises a superconducting closed looplayer, an insulating layer and a tunneling magnetoresistance device layer from bottom to top; the superconducting closed loop layer comprises two superconducting rings which are positioned in the same plane and are arranged in a mirror symmetry manner; each superconducting ring comprises a narrow area, a wide area and a connecting part used for connecting the narrow area and the wide area, and the narrow areas of the two superconducting rings are arranged close to each other; and the tunneling magnetoresistance device layer is located above the narrow areas of the two superconducting rings. The high-precision composite magnetic gradiometer has the advantages of being simple in structure and capable of carrying out ultra-high sensitivity testing on the magnetic field gradient.

Description

technical field [0001] The invention relates to the field of magnetic sensors, in particular to a high-precision composite magnetic gradiometer based on superconducting and tunneling magnetoresistance. Background technique [0002] Weak magnetic detection plays an important role and has broad application prospects in scientific research, national defense, industrial production and other fields. Due to the existence of background signals such as the geomagnetic field, there are great challenges in weak magnetic detection. The traditional magnetic shielding technology can suppress the background signal to a certain extent, but the cost is high, the processing is difficult, and the volume is large. The magnetic gradiometer can obtain effective weak magnetic signals without magnetic shielding, which provides an important way to develop the research and application of weak magnetic signals. For example, when used to measure biological magnetic signals, the magnetic gradiometer ...

AI Technical Summary

Problems solved by technology

[0003] At present, the detection of weak signal gradients is mainly based on the planar magnetic field gradiometer composed of superconducting quantum interference devices and magnetic field gradient coils. Two identical coils need to be prepared and placed symmetrically in the superconducting loop, and superconducting quantum interference must also be considered. The inductance matching problem between the interference device and the magnetic field gradient coil makes the preparation of the device difficult and the process is complicated; in addition, the superconducting quantum interference device itself is a superconducting ring, and the device has a non-zero response when the external magnetic field gradient is zero, and the ideal gradient signal cannot be output ; and the overall system of the device also has the disadvantages of large volume and low integration

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