Zero-field optical magnetometer based on spin-alignment

Abstract

Optically-pumped magnetometers are an important instrument for imaging biological magnetic signals without the need for cryogenic cooling. These magnetometers are presently available in the commercial market and utilize the principles of atomic alignment or orientation, enabling remarkable sensitivity and precision in the measurement of magnetic fields. This research focuses on utilizing a spin-aligned atomic ensemble for magnetometry at zero-field. A novel approach is introduced, which involves evaluating how the linear polarization of light rotates as it passes through the atomic vapor to null the magnetic field. Analytical expressions are derived for the resulting spin alignment and photodetection signals. Experimental results are provided, demonstrating good agreement with the theoretical predictions. The sensitivity and bandwidth of the magnetometer are characterized based on the detected polarization rotation signal. Lastly, the practical utility of the magnetometer for medical applications is demonstrated by successfully detecting a synthetic cardiac signal.

Main text is 11 pages and 7 figures, and the supplementary is 6 pages and 2 figures

References in corpus (6)

• Optical Magnetometer Array for Fetal Magnetocardiography
• Theory of double resonance magnetometers based on atomic alignment
• Unshielded portable optically pumped magnetometer for the remote detection of conductive objects using eddy current measurements
• Sensitivity of double resonance alignment magnetometers
• Alignment-based optically pumped magnetometer using a buffer gas cell
• Zero-field magnetometry based on the combination of atomic orientation and alignment

Cited by in corpus (5)

• Spin noise spectroscopy of an alignment-based atomic magnetometer
• Progress toward a zero-magnetic-field environment for ultracold-atom experiments
• Anomalous suppression of spin-exchange relaxation in alignment signals in cesium in ultra-weak magnetic fields
• Bistability of optical properties of cesium vapor due to collective interaction of alignment and orientation under strong spin exchange conditions
• Linear dichroism signals due to the alignment in the ground state of hydrogen-like atoms and their inversion in a single-beam optical pumping scheme