The original Makihara et al paper is paywalled unfortunately but this Stanford article says the researchers Takuma Makihara and Erik Szakiel developed “a way to pair a microscopic mechanical resonator with a superconducting qubit, which is an electrical circuit that can store quantum information and serve as a detector.”
According to the article this experiments results can only be described as a quantum like in behaviour. Apparently unlike a ‘classical resonating bell atom model’ which predicts a gradual ringing decline the research showed the ring abruptly stopped ringing and thus exhibited what could only be classified as a quantum jump. Not possible with a classical model they suggest.
Unfortunately the technical details of the paper are paywalled but from what available information is available in the article it seems this observed “jump” can still be made consistent with a classical model.
Notice in the article it is a “qubit” device which samples the ring down hundreds of times during the 2 millisecond time constraint of the experiment. Each sample length for the qubit must then be less than 100th of a millisecond. Essentially each qubit sample must then measure enough vibrational energy per this fractional time unit to trigger a positive +1 reading in the qubit. Below this, the qubit cannot receive enough vibrational energy within each qubit sample’s <1/100ms time limit to trigger a positive reading. Even if the resonating device were still vibrating and producing the ring down as its vibrations declined gradually in strength.
In other words there still can be a classical ring down occurring from the resonator in the experiment but the qubit measuring device cannot measure the vibrations from the resonator when the resonators vibrational energy decreases to below the qubits detection threshold for each of the qubit samples <1/100ms time length. The qubit needs at least a certain amount of energy to trigger a 1 reading. Below that it will trigger a zero reading even if the resonator is still vibrating slightly.
No quantum theory is needed to describe the classical ring down of a resonating system. It’s just that the “quantum” device or “qubit” cannot measure resonant energy below a certain energy threshold during the time threshold constraint imposed on it by its <1/100millisecond sample time length.
