The phrase “quantum leap” is most often used by people who know sod all about quantum mechanics. Usually what they mean to say is that whatever they’re talking about provides a huge step forward. If they knew anything, they would know that quantum mechanics is the study of subatomic particle interactions.
By its own definition, a quantum leap is a miniscule jump. The classic example is a single atom; when it absorbs a certain amount of energy, an electron orbiting the nucleus instantly jumps from a low energy state to a higher energy state. An excited electron can also fall back to a lower energy state while spontaneously emitting a photon in the process. These are said to be quantum leaps as they involve discreet, discontinuous energy levels. Ironically, I first heard the phrase “quantum leap” being used by an ignorant science tv show presenter.
In physics, a quantum leap or quantum jump is a change of an electron from one energy state to another within an atom….. In real physical systems a quantum leap is not necessarily a large change, and can in fact be very insignificant….. In the popular sense, the term is usually applied to mean a large or significant change, which is thus not strictly correct.