Nanomechanical state amplifier

In our recent article “Nanomechanical state amplifier based on optical inverted pendulum” (Communications Physics, 2025), we present an experimentally verified protocol for the linear amplification of a nanomechanical state – specifically, the position of a silica nanoparticle optically trapped in vacuum – achieved by rapid switching between a parabolic and an inverted parabolic potential. This nanomechanical state amplifier (NMSA) enables the “stretching” of a quantum or stochastic state to dimensions comparable to the optical wavelength, thereby enhancing the sensitivity of weak-force measurements. The analysis shows that the protocol introduces only minimal distortion while preserving an excellent signal-to-noise ratio across different initial states. This approach opens a pathway toward employing nanomechanical state amplifiers for ultrasensitive measurements in the quantum regime, including applications in studies of the transition between classical and quantum physics.