An ordinary sensor is like a scale that always shakes a little on its own. Even in total silence and at zero temperature, every particle jitters — this is quantum jitter, and it limits the precision of any measurement.
Scientists took a tiny glass speck (thinner than a human hair), suspended it in a laser beam, and made it jitter not in the usual way but in a special mode. They 'squeezed' that jitter: reduced it in one direction to better hear kicks in another. That way they caught a single impulse with a force of just 6.9 keV/c — like a fly hitting a spiderweb, but billions of times weaker.
This trick could make ultra-sensitive sensors even more sensitive. For example, they could pick up gravitational waves from distant black hole collisions or search for dark matter particles streaming through Earth.
as written by the authors arXiv:2601.19392
The sensitivity of a mechanical transducer is ultimately limited by its inherent quantum fluctuations. Here, we use an optically levitated nanoparticle to measure impulsive forces smaller than the particle's zero-point momentum uncertainty. Our approach relies on reversibly squeezing the levitated particle's center-of-mass motion to coherently amplify the perturbation. We demonstrate resolving single impulsive-force kicks as small as 6.9 keV/c, a value 0.6 dB below the sensor's zero-point value.
Quantum jitter isn't instrument noise — it's a property of matter itself. Even in absolute vacuum, a particle can't come to a complete standstill: it always wobbles a bit, like a bobber on water.
In the movie 'Interstellar', characters use ultra-sensitive sensors to find gravitational anomalies — similar technology could become reality.