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arXiv:2601.00425

Chip-scale superconducting quantum gravimeter combining a SQUID, a transmon, and a nanomechanical resonator

Salman Sajad Wani, Mughees Ahmed Khan, Abrar Ahmed Naqash, Saif Al-Kuwari

quant-phSubmitted Jan 1, 2026• Announced Jan 2, 2026• 0 citations• Revised May 1, 2026 (v2)
v1 · Jan 1, 2026v2 · May 1, 2026
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Abstract

Precise gravitational measurements are vital for geophysics and inertial navigation, but compact gravimeters with high measurement bandwidth remain difficult to realize. We propose and analyze a chip-scale superconducting gravimeter in which a flux-tunable transmon qubit is coupled to a high quality factor ($Q_m$) nanomechanical beam. The beam is embedded in a SQUID loop placed in parallel with the qubit's flux-tunable SQUID; gravity induced beam displacement therefore modulates the qubit frequency through the SQUID flux and is mapped onto the qubit's geometric phase. A stroboscopic readout at mechanical revival times suppresses qubit mechanics dephasing, yielding a projected sensitivity of $10^2$--$10^3\,\mathrm{nGal}/\sqrt{\mathrm{Hz}}$ with sub-millisecond interrogation times. Electrical \emph{in situ} tunability and microwave-based calibration make this architecture a practical route toward compact, high-bandwidth on-chip gravimetry.

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