Stanford Physicists Track 1 Phonon Vanishing in First Quantum Jump of Sound

3 articles · Updated · The Brighter Side of News · Sep 21

A microscopic Stanford resonator was watched in real time as a single phonon abruptly dropped from 1 to 0, marking the first direct observation of a quantum jump in sound.
A superconducting qubit made repeated quantum-nondemolition checks of the resonator’s energy, letting researchers infer the jump without immediately destroying the state; the measurements were about 99% nondestructive.
The lithium-niobate device held mechanical energy for roughly 2 milliseconds at gigahertz frequencies, long enough for about 170 useful parity checks during one intrinsic phonon lifetime and up to 294 consecutive measurements in a run.
The work extends quantum-jump observations from atoms and photons to mechanical motion, giving researchers a way to monitor quantum behavior inside solid devices.
Stanford said the technique could aid sound-based quantum error correction and ultrasensitive sensing of mass, force, acceleration and strain, though practical systems still need better coherence, readout fidelity and integration.