Harmonic oscillator’s most ‘classical-like’ state exhibits nonclassical behavior

Showing just how blurry the boundary is between the quantum and classical worlds, physicists in a new study have theoretically demonstrated that a macroscopic oscillating object initially in a classical-like coherent state can exhibit nonclassical behavior—namely, it can violate the classical notion of realism by not having a single definite state at any given moment. Instead, the oscillator has one of two states with a certain probability, as theoretically shown by non-invasive measurements of the oscillator’s position at different times.