In quantum mechanics, the wave function describes the state of a particle or system. The Schrödinger equation is a fundamental equation that governs the behavior of quantum systems. According to the Schrödinger equation, the wave function evolves in a deterministic and unitary manner over time.
However, when a measurement is made on a quantum system, a phenomenon known as wave function collapse or wave function reduction occurs. Wave function collapse refers to the sudden and non-deterministic change in the state of the system as a result of measurement.
When a measurement is performed on a quantum system, the wave function of the system "collapses" or "reduces" into one of the eigenstates corresponding to the measured observable. In other words, the wave function transitions from a superposition of multiple possible states to a single definite state.
The specific outcome of the collapse is probabilistic and follows the principles of quantum mechanics. The probability of obtaining a particular measurement outcome is given by the squared magnitude of the amplitude associated with the corresponding eigenstate in the superposition.
The collapse of the wave function is a key aspect of quantum mechanics and distinguishes it from classical physics. It introduces an element of randomness and irreversibility into the behavior of quantum systems. The exact mechanism and interpretation of wave function collapse are still subjects of debate and interpretation in the field of quantum mechanics.