Stanford researchers have, for the first time, directly observed sound making the abrupt energy transitions known as quantum jumps. By tracking individual phonons—the smallest discrete units of sound—they watched these particles vanish from one energy state and reappear in another in real time.
The result moves quantum monitoring, long applied to photons and atoms, into the acoustic domain. The ability to watch phonon jumps as they happen could help engineers design better quantum error correction, since sudden state changes are a key source of noise in quantum systems, and could lead to new types of sensitive biological sensors that respond to minute vibrations.
Because the report comes from a single source, there are no conflicting findings to compare. The researchers describe the work as a breakthrough, but the source gives no details about peer review or when the potential applications might reach practical use.