Threshold sensitivity of quantum magnetometric instruments

James Higbie

Roland Lammegger, Arno Huss, Stefan Leopold Hatzl +1 more

Walter Ayala

The design of the Multimodal Instrument for Spin Ensemble Characterization(MIMS v7.4.1) is presented. The instrument executes seven independent measure-ment protocols on solid-state spin ensembles, operating under controlled vacuum con-ditions to minimize environmental decoherence.• Standard Protocol: Multi-exponential relaxation dynamics.• RAE Protocol: Controlled interruption of entanglement.• TEBC Protocol: Response under magnetic field near the correlation loss threshold(effective phenomenological model).• PDE Protocol: Diagnosis of response patterns under magnetic constraint.• REU Protocol: Correlational restoration with synchronized pulses.• SBR Protocol: Edge-of-rupture sensor (regulated phenomenological model).• SBR-REU Protocol: Combined amplification and restoration mode.Eight sensor channels (expandable to nine with Mössbauer in Plan B) monitor fourspin ensembles. Entanglement operates in micro-windows (∼ 100 µs–1 ms) withineach macroscopic cycle.The vacuum chamber (< 10−5 mbar) eliminates collisional decoherence. PlanB incorporates Mössbauer for independent cross-validation.Computational simulation (Appendix E) validates the statistical architecture.All protocols achieve positive detection under controlled conditions. ChannelsCH4 (SQUID) and CH6 (SERF) dominate magnetometric sensitivity; secondarychannels provide instrumental veto, cross-validation, and pattern classification.Construction cost: $850,000–$5,000,000+ USD. Timeline: 66–78 months.

B. V. Vasiliev, V. G. Grebinnik, V. G. Simkin

Derek F. Jackson Kimball, Louis Jacome, Srikanth Guttikonda +2 more

Atomic spin polarization of alkali atoms in the ground-state can survive thousands of collisions with paraffin-coated cell walls. The resulting long spin-relaxation times achieved in evacuated, paraffin-coated cells enable precise measurement of atomic spin precession and energy shifts of ground-state Zeeman sublevels. In the present work, nonlinear magneto-optical rotation with frequency-modulated light (FM NMOR) is used to measure magnetic field-induced spin precession for rubidium atoms contained in a paraffin-coated cell. The magnetometric sensitivity of FM NMOR for the rubidium D2 line is studied as a function of light power, detuning, frequency-modulation amplitude, and rubidium vapor density. For a 5-cm-diameter cell at temperature T≈35 °C, the optimal shot-noise-projected magnetometric sensitivity is found to be 2×10−11 G/Hz (corresponding to a sensitivity to spin precession frequency of ≈10 μHz/Hz or a sensitivity to Zeeman sublevel shifts of ≈4×10−20 eV/Hz).

Vladimir B. Braginsky