a sudden alteration in the energy level of an atom or molecule
2.
any sudden and extensive change or advance, as in a program or policy
quantum jump in American English
noun
1. Physics
an abrupt transition of a system described by quantum mechanics from one of its discrete states to another, as the fall of an electron in an atom to an orbit of lower energy
2.
any sudden and significant change, advance, or increase
Also called: quantum leap
Word origin
[1925–30]This word is first recorded in the period 1925–30. Other words that entered Englishat around the same time include: chain reaction, hot spot, reflex camera, runout, turnaround
Examples of 'quantum jump' in a sentence
quantum jump
This is a quantum jump or leap, and it is a very small distance indeed.
Times, Sunday Times (2012)
In this context, evolution would need to make an invisible quantum jump when life becomes human.