A systematic study of stem-induced effects on transverse spin relaxation of noble gases in atomic gas cells

Glass-blown atomic gas cells provide a fundamental basis for high precision atomic sensors, such as optically pumped magnetometers, Rydberg RF sensors, and atomic spin gyroscopes. To enhance the sensitivity of these sensors, it is essential to achieve long transverse spin relaxation times (T₂) for noble gases, which can be limited by various decoherence mechanisms including spin exchange collisions and magnetic field gradients. In particular, geometric asymmetry of the cell can induce inhomogeneous electric field gradients as well as exacerbate the effects of magnetic field gradients, thereby degrading sensor performance. Here, we demonstrate the effects of cell geometry on the transverse spin relaxation of ¹²⁹Xe and ¹³¹Xe. First, we report a novel technique for sealing atomic gas cells with a stem using a resistive heating wire, which enables systematic and consistent fabrication. Utilizing this method, we fabricate cells with varying stem lengths and characterize their geometry based on the transverse spin relaxation rate of ¹²⁹Xe. Then, we compare the quadrupole shifts of ¹³¹Xe among these cells to systematically study the stem-induced effects on the transverse spin relaxation. This work will address the performance degradation of miniaturized atomic sensors arising from the cell geometry, leading to the improvement of their sensitivity.