The Whisper Faded: A Quantum Trick Bypasses a Fundamental Limit ⚡ экспресс
In the Einstein–Bohr thought experiment with a recoiling slit, the fundamental limitation arises from zero-point fluctuations of the atomic slit—the spatial standard quantum limit (SQL). Overcoming this limit has been achieved by active quantum engineering of a single atom-slit’s state. A nonadiabatic ‘quench-evolve-quench’ protocol prepares a squeezed state of atomic motion, dynamically redistributing uncertainty in phase space to suppress which-path information. The recovered interference visibility is 0.938 (error –0.008/+0.004), violating the SQL (0.819) by more than 10 standard deviations, corresponding to an effective squeezing of 7.6(2) dB. Nonlinear dynamics induced by the Kerr effect are observed; the traditional interferometer is reimagined as a tool for Wigner tomography of continuous variables. This work bridges the foundations of quantum mechanics with cutting-edge metrology.
Even at absolute rest, atoms emit a faint noise — unavoidable quantum jitter. In the debates between Einstein and Bohr, this noise, like an unceasing whisper, blurs the interference fringes from an atomic slit. Overcoming this limit was considered impossible.
First, the atom was deliberately excited with optical tweezers, then a special protocol squeezed its vibrations. Information about the trajectory was erased, and the fringes achieved a contrast of 0.938 — 10 standard deviations above the previous limit (0.819). The whisper nearly vanished, and sharpness soared. This is how ultra-precise quantum sensors are born.
🎯 The squeezing effect here reaches 7.6 decibels — roughly the volume difference between a normal conversation and a whisper in a library.