Geometric-Phase GW Sensing in Space: Ramsey Optomechanics Co-flying with LISA/Taiji

Nandi & Scholtz (2025) argue that low-frequency GWs can imprint purely quantum geometric phases in optomechanical systems, distinct from classical strain signatures. We propose a hosted payload—compact, cryo-capable optomechanical Ramsey interferometers—on a LISA/Taiji-like platform. The concept leverages spacecraft-grade pointing (enabled by two-dimensional point-ahead angle mechanisms; Zhu et al. 2024) and benefits from the benign plasma-induced OPD landscape after TDI (Su Wei 2021) because the key observable is an internal quantum phase, not a long-arm path difference. The new angle is to co-analyze these geometric-phase readouts with μHz–nHz FRB timing baselines (Lu, Wang, Xiao 2024), which measure the local GW field in the Solar System. A correlated detection between a geometric-phase sensor and FRB timing would be a uniquely robust confirmation of low-frequency GWs, minimizing degeneracy with instrumental drifts or plasma systematics. This line of work challenges the standard strain-only paradigm by opening an independent quantum channel to GWs. Success would provide a complementary low-frequency window, stress-test GR in a novel regime, and de-risk future quantum-limited spaceborne GW sensing.

References:

1. A New Probe of $\mu$Hz Gravitational Waves with FRB Timing. Zhiyao Lu, Lian-Tao Wang, Huangyu Xiao (2024).
2. Development and analysis of two-dimensional point-ahead angle mechanism for space gravitational-wave detection.. Weizhou Zhu, Yong Xie, Yuchen Qian, J. Jia, Liang Zhang, Xue Wang (2024). Review of Scientific Instruments.
3. Quantum Geometric Phases as a New Window on Gravitational Waves. Partha Nandi, F. G. Scholtz (2025).
4. Analyses of Laser Propagation Noise for TianQin Gravitational Wave Observatory Based on the Global Magnetosphere MHD Simulation. Su Wei (2021).