Quantum Mechanics Quantum mechanics, born out of the early 20th century's scientific revolution, is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. Theory of Quantum Entanglement Quantum entanglement, a fundamental concept in quantum mechanics, describes a phenomenon where two or more particles become linked and the state of one can instantly affect the state of another, no matter the distance between them. Entangled particles are correlated in such a way that their states are dependent on each ot