Comment by Jonghwa_Lee

Thanks for the sharp question. You hit the core challenge. I am targeting a sensitivity of 10^{-18} seconds, which is within the range of modern Sr-87 optical lattice clocks (current stability \approx 10^{-19}). While the effect of information density (\Delta S_{info}) is expected to be extremely subtle compared to mass (G), the differential measurement (Entangled vs. Non-entangled) allows me to filter out common-mode noise. Even if I get a null result, establishing an upper bound on the coupling constant \alpha would be a significant contribution. I'm putting my bet on the high complexity of the GHZ state.