Tunable homogeneous kG magnetic field production using permanent magnets

Area of Science:

• Atomic, Molecular, and Optical Physics
• Magnetics and Magnetometry

Background:

• Atomic vapor cells are essential for various quantum technologies and precision measurements.
• Achieving stable and tunable magnetic fields is critical for controlling atomic states and enabling advanced imaging techniques.

Purpose of the Study:

• To design and characterize a tunable permanent ring magnet system for generating stable axial magnetic fields.
• To provide an alternative method for imaging through atomic vapors within large magnetic fields.

Main Methods:

• Utilized layered, concentric, off-the-shelf N42 neodymium-iron-boron axially magnetized ring magnets.
• Organized magnets into four cylindrical brass holders with adjustable separation for field tuning.
• Performed magnetic field computations and Marquardt-Levenberg fits to experimental data.

Main Results:

• Achieved a tunable axial magnetic field ranging from 1.80(5) to 2.67(9) kG.
• Demonstrated an RMS variation of less than 4% over the vapor cell length.
• Calculated field inhomogeneity below 5% radially and 12% longitudinally within the specified volume.

Conclusions:

• The developed permanent magnet arrangement offers a stable and tunable axial magnetic field suitable for atomic vapor cell applications.
• The system demonstrates excellent agreement between theoretical calculations and experimental measurements.
• Presents a viable alternative for atomic vapor imaging in demanding magnetic field environments.