SQUID array planar and axial gradiometer

An intrinsic superconducting quantum interference device (SQUID) gradiometer comprising:

• a first SQUID array having at least two SQUIDs, wherein the first SQUID array has upper and lower terminals located on opposite sides of the first SQUID array, wherein the upper terminal is configured to receive a bias signal;
• and
• a second SQUID array that is identical to, oriented the same as, and located in close proximity to the first SQUID array, wherein the second SQUID array's upper terminal is grounded and its lower terminal is electrically connected to the first SQUID array's lower terminal such that a measured voltage difference between the first SQUID array's upper terminal and the second SQUID array's upper terminal represents a net current generated by a gradient magnetic field where near-field measurements are cancelled, and wherein the intrinsic SQUID gradiometer is designed to provide the measured voltage difference that is directly proportional to the magnetic field gradient without being connected to any external coils or flux transducers.

An intrinsic superconducting gradiometer comprising:

• a first array having at least two superconducting devices, wherein the first array has upper and lower terminals located on opposite sides of the first array, wherein the upper terminal is configured to receive a bias signal, and wherein each superconducting device comprises at least one Josephson junction loop and is configured to function as a magnetic-to-voltage transducer;
• and
• a second array that is identical to, oriented the same as, and located in close proximity to the first array, wherein the second array's upper terminal is grounded and its lower terminal is electrically connected to the first array's lower terminal such that a measured voltage difference between the first array's upper terminal and the second array's upper terminal represents a net current generated by a gradient magnetic field where near-field measurements are cancelled, and wherein the intrinsic superconducting gradiometer is designed to provide the measured voltage difference that is directly proportional to the magnetic field gradient without being connected to any external coils or flux transducers.