As a tool for physics, quantum states grew out of states in classical mechanics. A classical dynamical state consists of a set of dynamical variables with well-defined real values at each instant of time. For example, the state of a … 展开

The process of describing a quantum system with quantum mechanics begins with identifying a set of variables defining the quantum state of the system. The set will contain 展开

The quantum state after a measurement is in an eigenstate corresponding to that measurement and the value measured. Other aspects of the state … 展开

Wave functions represent quantum states, particularly when they are functions of position or of momentum. Historically, definitions of quantum states used wavefunctions before the more formal methods were developed. The wave function is a complex … 展开

Measurements, macroscopic operations on quantum states, filter the state. Whatever the input quantum state might be, repeated identical … 展开

The same physical quantum state can be expressed mathematically in different ways called representations. The position wave function is one … 展开

Pure states as rays in a complex Hilbert space
Quantum physics is most commonly formulated in terms of linear algebra, as follows. Any given system … 展开