Low-frequency 129Xe nuclear spin oscillator with optical spin detection

Low energy precision experiments to limit extensions of the SM

“…An experiment under way at TUM, which uses squids to monitor the difference of precession frequencies for two samples in opposite electric fields, may provide several orders of magnitude improvement compared to 199 Hg. An active maser approach using 129 Xe is under development in Tokoyo Institute of Technology [58].…”

Active nuclear spin maser oscillation with double cell

“…The present study aims at measuring the EDM in the diamagnetic atom 129 Xe to the order of |d| = 10 −28 ecm, beyond the present upper limit [1]. In the EDM measurement, we employ an active nuclear spin maser [2,3] which enables us to sustain the spin precession of 129 Xe over a long measurement duration. The spin precession of 129 Xe is detected optically through transverse polarization of Rb spins.…”

“…An oscillating magnetic field is applied in synchronization with the spin precession, thereby preventing transverse spin relaxation. Previous development on the active spin maser has achieved a precision δν = 9.3 nHz for the frequency averaged over a single-shot observation of continued precession sustained for 3 × 10 4 s [3]. It is important to note, however, that the above frequency precision will be meaningful to an EDM detection only if the magnetic field acting on the spins is stable, or if its average in the same time period is known, to an equal or higher level of precision.…”

“…It is important to note, however, that the above frequency precision will be meaningful to an EDM detection only if the magnetic field acting on the spins is stable, or if its average in the same time period is known, to an equal or higher level of precision. A comagnetometer using 3 He was incorporated into the active spin maser system in order to cancel out the drifts in the external magnetic field B 0 which are commonly sensed by 129 Xe and 3 He [4]. However the drifts in the frequency shift due to contact interaction of 129 Xe spin with polarized Rb valence electrons can not be fully removed by the 3 He co-magnetometer, because of the different strengths for the Xe and Rb- 3 He contacts [5,6].…”

“…A comagnetometer using 3 He was incorporated into the active spin maser system in order to cancel out the drifts in the external magnetic field B 0 which are commonly sensed by 129 Xe and 3 He [4]. However the drifts in the frequency shift due to contact interaction of 129 Xe spin with polarized Rb valence electrons can not be fully removed by the 3 He co-magnetometer, because of the different strengths for the Xe and Rb- 3 He contacts [5,6]. Therefore a double-cell geometry [1] in which the gas volume is divided into one section for the optical pumping and one section for masing and optical spin detection was employed.…”