Enhanced Nuclear‐Spin Coherence in Millimeter‐Scale Anti‐Relaxation‐Coated Cells for Rb‐ ¹²⁹ Xe Comagnetometers

ABSTRACT

The transverse coherence time of in bare millimeter‐scale Pyrex cells is typically below 10 s, which limits the performance of chip‐scale noble‐gas comagnetometers. Here we coat cubic Pyrex cells with inner dimensions of using silicone, silane, and octadecyltrichlorosilane (OTS). The silicone‐ and OTS‐coated cells exhibit transverse coherence times exceeding 100 s, more than an order of magnitude longer than those of uncoated cells. Incorporating an OTS‐coated cell into an Rb‐ comagnetometer increases the rotation scale factor and yields a sensitivity of at 1 Hz, approximately a factor of two better than that obtained with an uncoated cell under similar conditions. These results indicate anti‐relaxation‐coated millimeter‐scale cells as a practical route toward compact noble‐gas spin sensors with improved inertial sensitivity.