We experimentally demonstrate quantum squeezing in a snap using a harmonic oscillator, a textbook concept that was never realized. Quantum squeezed states lie at the heart of quantum sensing and quantum information processing. However, to create a high fidelity squeezed state, a long creation time in a high quality factor oscillator is necessary to avoid decoherence and errors, limiting the wide usage of quantum squeezed states for practical applications. The frequency jump oscillator has been widely used in discussing the nonadiabaticity of quantum mechanics. The consideration to use this textbook concept for quantum squeezing started in the late 1980s.

The squeezing dynamics in this method do not rely on quantum evolution, and thus the time to create a squeezed state is not limited by the quantum speed limit. Such a fast preparation allows the squeezed state to decouple from decoherence. We verify this in an optical lattice potential where decoherence from anharmonicity prevents the creation of the squeezed state using conventional quantum evolution methods. Our demonstration can be applied to other quantum systems for continuous-variable quantum information to create instantaneous quantum gate operation. We apply this method to amplify a coherent state created by a sudden shift of the potential minimum. The rapid amplification of the coherent state can be used in speeding up quantum dynamics and quantum sensing of motion and force.