A spin self-sustaining atomic magnetometer for high-precision measurements in large magnetic fields

Measurement of magnetic fields by monitoring the Larmor precession of atomic spins is commonly used nowadays because of the high sensitivity and absolute measurement. This paper proposes a novel atomic magnetometer based on the self-sustaining method for large and fluctuating magnetic fields. In combination with the indefinitely persist Larmor precession signal, the sensitivity of the magnetometer increases following a much faster tau(-1) rule beyond the atomic coherence lifetime. The maximum magnetic field have been experimentally demonstrated up to 40000 nT, the sensitivity achieved is 20 pT/root Hz and the frequency response bandwidth is 5 kHz, respectively. This magnetic field sensor is advantageous for applications requiring high sensitivity over a wide dynamic range such as geology and space physics.