Single-Electron Detection with a SQUID: Toward Quantum-Limited, Relativistic Detection
ORAL
Abstract
The most recent measurement of the electron magnetic moment in Bohr magnetons, μs/μB = g/2 = 1.001 159 180 59 (13) is the most precise determination of any fundamental particle. Its comparison with its theory prediction provides the most precise test of the Standard Model of Particle Physics. The current precision is limited by two effects– a lineshape broadening related to the trapped electron’s temperature and a cavity shift arising from coupling of the electron to the microwave modes of its confining trap-cavity.
An extensive new apparatus, including a near-quantum limited SQUID amplifier and optimized Penning trap has been commissioned. A twenty-fold reduction in the electron's temperature will reduce the lineshape broadening and improve the precision of a non-destructive quantum state readout. The improved trap geometry and readout supports a transition toward a quantum non-demolition detection based on a relativistic mass increase. Cavity shifts will be better characterized and corrected for due to a factor of five reduction in the trap volume leading to mode density suppression.
One electron has been detected in the new apparatus with the highest signal-to-noise ratio ever observed. Careful characterization of the detector and apparatus identifies surmountable challenges to be addressed, establishing a clear path toward the next-generation, far more precise measurements of the electron and positron magnetic moments.
An extensive new apparatus, including a near-quantum limited SQUID amplifier and optimized Penning trap has been commissioned. A twenty-fold reduction in the electron's temperature will reduce the lineshape broadening and improve the precision of a non-destructive quantum state readout. The improved trap geometry and readout supports a transition toward a quantum non-demolition detection based on a relativistic mass increase. Cavity shifts will be better characterized and corrected for due to a factor of five reduction in the trap volume leading to mode density suppression.
One electron has been detected in the new apparatus with the highest signal-to-noise ratio ever observed. Careful characterization of the detector and apparatus identifies surmountable challenges to be addressed, establishing a clear path toward the next-generation, far more precise measurements of the electron and positron magnetic moments.
*The project is supported by NSF1903756 and 2110565; the Templeton Foundation for detector development; DOE SQMS Center for low-loss trap cavity development
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Presenters
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Benedict A Sukra
- Northwestern University