A magnetic field concentrating or guiding device can include one or more coils, and one or more foil, tape and/or bulk superconductor structures disposed in one or more predetermined positions With relation to the coils. The one or more superconductor structures can form one or more magnetic field carrying regions. During operation, current passing through the one or more coils can generate one or more magnetic fields that are compressed or guided in the magnetic field carrying regions.

An exemplary magnetic field measurement system includes a wearable sensor unit and a single controller. The wearable sensor unit includes a plurality of magnetometers. The single controller is configured to generate a single clock signal and use the single clock signal to drive one or more components within the magnetometers.

An exemplary controller may include a single clock source configured to generate a single clock signal used to drive one or more components within a plurality of magnetometers and a plurality of differential signal measurement circuits configured to measure current output by a photodetector of each of the plurality of magnetometers.

An inductor comprises an excitation coil with an excitation coil axis and at least one shielding coil with a respective shielding coil axis. The excitation coil axis and the shielding coil axis define an angle δ, wherein applies: 60°≤δ≤120°, preferably 75°≤δ≤105°, and preferably 85°≤δ≤95°. The inductor is shielded and enables in an easy and flexible manner the attenuation of electric and magnetic fields.

An exemplary magnetic field measurement system includes a wearable sensor unit and a single controller. The wearable sensor unit includes a plurality of magnetometers and a magnetic field generator configured to generate a compensation magnetic field configured to actively shield the magnetometers from ambient background magnetic fields. The single controller is configured to interface with the magnetometers and the magnetic field generator.

An exemplary magnetic field measurement system includes a wearable sensor unit and a controller. The wearable sensor unit includes 1) a magnetometer comprising a photodetector and 2) a magnetic field generator configured to generate a compensation magnetic field configured to actively shield the magnetometer from ambient background magnetic fields. The controller is configured to interface with the magnetometer and the magnetic field generator and includes a differential signal measurement circuit configured to measure current output by the photodetector.

An exemplary magnetic field measurement system includes a wearable sensor unit that includes a magnetometer, a magnetic field generator configured to generate a compensation magnetic field configured to actively shield the magnetometer from ambient background magnetic fields, a twisted pair cable interface assembly electrically connected to the magnetometer, and a coaxial cable interface assembly electrically connected to the magnetic field generator.

An electronic package includes a mounting platform for mounting an electrically small device, at least one coil, and an insulator. The coil regulates a magnetic field through the electrically small device at the mounting platform. The coil is adapted to conduct a current for nullifying the magnetic field through the electrically small device at the mounting platform. The insulator is between the mounting platform and the coil for isolating the electrically small device from the coil. An electronic circuit includes this electronic package and the electrically small device mounted at the mounting platform of the electronic package. The electrically small device can be a quantum device and/or a topological device when cooled to a cryogenic temperature. The magnetic field is nullified to prevent the magnetic field from adversely affecting the electrically small device.

A leakage magnetic field shielding device includes: a leakage magnetic field determining unit for determining phase and magnitude of a leakage magnetic field based on information obtained from a power supply device and a current collector device; a shielding current controller for determining a shielding current based on the phase and magnitude of the leakage magnetic field and supplying the determined shielding current to the leakage magnetic field shielding device; and a shielding unit for shielding the leakage magnetic field by generating a shielding magnetic field in accordance with the supply of the shielding current. The shielding unit has a multiple resonance characteristic depending on an arrangement of capacitors and coils and is disposed to surround the power supply device or the current collector device. The shielding magnetic field has resonance frequencies canceling magnetic fields corresponding to fundamental frequency and multiple frequency of the leakage magnetic field.

A gradient coil for an MRI apparatus is disclosed, comprising a main coil layer and a shielding coil layer. The shielding coil layer is arranged around the main coil layer, which includes an X, Y, and Z main coil set, and an X and Y end shielding coil set. The X end shielding coil set is connected in series with the X main coil set and used to form a shielding magnetic field in a direction opposite to the X direction. The Y end shielding coil set is connected in series with the Y main coil set and used to form a shielding magnetic field in the opposite direction to the Y direction. In the Z direction, the X end shielding coil set and Y end shielding coil set are disposed outside an imaging region enclosed by the main coil layer.