Pure State


Pure State

 

A pure state of a quantum-mechanical system is a state that is characterized by specifying the complete set of possible values of the dynamic variables that define the state of the system. A pure state is described by the wave function of the dynamic variables and is a basic concept of quantum mechanics. A superposition of wave functions—that is, the sum of such functions with arbitrary complex coefficients—also describes a pure state of a system. A pure state is often simply called a quantum state, although there is a more general case, namely the mixed state, in quantum mechanics. (SeeMIXED STATE.)