Mathematical entity to describe the probability of each possible measurement on a system
Part of a series of articles about
Quantum mechanics
Schrödinger equation
Introduction
Glossary
History
Background
Classical mechanics
Old quantum theory
Bra–ket notation
Hamiltonian
Interference
Fundamentals
Complementarity
Decoherence
Entanglement
Energy level
Measurement
Nonlocality
Quantum number
State
Superposition
Symmetry
Tunnelling
Uncertainty
Wave function
Collapse
Experiments
Bell's inequality
Davisson–Germer
Double-slit
Elitzur–Vaidman
Franck–Hertz
Leggett–Garg inequality
Mach–Zehnder
Popper
Quantum eraser
Delayed-choice
Schrödinger's cat
Stern–Gerlach
Wheeler's delayed-choice
Formulations
Overview
Heisenberg
Interaction
Matrix
Phase-space
Schrödinger
Sum-over-histories (path integral)
Equations
Dirac
Klein–Gordon
Pauli
Rydberg
Schrödinger
Interpretations
Bayesian
Consistent histories
Copenhagen
de Broglie–Bohm
Ensemble
Hidden-variable
Local
Superdeterminism
Many-worlds
Objective collapse
Quantum logic
Relational
Transactional
Von Neumann–Wigner
Advanced topics
Relativistic quantum mechanics
Quantum field theory
Quantum information science
Quantum computing
Quantum chaos
EPR paradox
Density matrix
Scattering theory
Quantum statistical mechanics
Quantum machine learning
Scientists
Aharonov
Bell
Bethe
Blackett
Bloch
Bohm
Bohr
Born
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de Broglie
Compton
Dirac
Davisson
Debye
Ehrenfest
Einstein
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Gutzwiller
Heisenberg
Hilbert
Jordan
Kramers
Lamb
Landau
Laue
Moseley
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Onnes
Pauli
Planck
Rabi
Raman
Rydberg
Schrödinger
Simmons
Sommerfeld
von Neumann
Weyl
Wien
Wigner
Zeeman
Zeilinger
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In quantum physics, a quantum state is a mathematical entity that embodies the knowledge of a quantum system. Quantum mechanics specifies the construction, evolution, and measurement of a quantum state. The result is a quantum-mechanical prediction for the system represented by the state. Knowledge of the quantum state, and the quantum mechanical rules for the system's evolution in time, exhausts all that can be known about a quantum system.
Quantum states may be defined differently for different kinds of systems or problems. Two broad categories are
wave functions describing quantum systems using position or momentum variables and
the more abstract vector quantum states.
Historical, educational, and application-focused problems typically feature wave functions; modern professional physics uses the abstract vector states. In both categories, quantum states divide into pure versus mixed states, or into coherent states and incoherent states. Categories with special properties include stationary states for time independence and quantum vacuum states in quantum field theory.
In quantum physics, a quantumstate is a mathematical entity that embodies the knowledge of a quantum system. Quantum mechanics specifies the construction...
In quantum field theory, the quantum vacuum state (also called the quantum vacuum or vacuum state) is the quantumstate with the lowest possible energy...
A quantum computer is a computer that takes advantage of quantum mechanical phenomena. On small scales, physical matter exhibits properties of both particles...
proximity in such a way that the quantumstate of each particle of the group cannot be described independently of the state of the others, including when...
of all quantum physics, which includes quantum chemistry, quantum field theory, quantum technology, and quantum information science. Quantum mechanics...
location to the next, quantum teleportation only transfers quantum information. The sender does not have to know the particular quantumstate being transferred...
Quantum information is the information of the state of a quantum system. It is the basic entity of study in quantum information theory, and can be manipulated...
In quantum computing and specifically the quantum circuit model of computation, a quantum logic gate (or simply quantum gate) is a basic quantum circuit...
entanglement Quantum fiction Quantum field theory Quantum lithography Quantum mechanics Quantum mind Quantum mysticism Quantum number Quantum optics Quantum sensor...
In quantum information science, the Bell's states or EPR pairs: 25 are specific quantum states of two qubits that represent the simplest examples of...
for finding a probability involves combining a quantumstate, which mathematically describes a quantum system, with a mathematical representation of the...
non-quantum) communication. For example, it is impossible to copy data encoded in a quantumstate. If one attempts to read the encoded data, the quantum state...
In quantum computing, the quantum Fourier transform (QFT) is a linear transformation on quantum bits, and is the quantum analogue of the discrete Fourier...
Quantum superposition is a fundamental principle of quantum mechanics that states that linear combinations of solutions to the Schrödinger equation are...
physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, one of the simplest quantum systems displaying the...
Quantum machine learning is the integration of quantum algorithms within machine learning programs. The most common use of the term refers to machine learning...
In quantum computing, a quantum algorithm is an algorithm that runs on a realistic model of quantum computation, the most commonly used model being the...
quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics might correspond to experienced reality. Although quantum...
formulations of quantum mechanics continue to be used today. At the heart of the description are ideas of quantumstate and quantum observables, which...
In physics, a quantumstate space is an abstract space in which different "positions" represent, not literal locations, but rather quantum states of some...
A quantum machine is a human-made device whose collective motion follows the laws of quantum mechanics. The idea that macroscopic objects may follow the...
0.10 are still considered quite fluorescent. Quantum yield is defined by the fraction of excited state fluorophores that decay through fluorescence:...
In quantum mechanics, wave function collapse, also called reduction of the state vector, occurs when a wave function—initially in a superposition of several...
Quantum mechanics is the study of matter and its interactions with energy on the scale of atomic and subatomic particles. By contrast, classical physics...
Quantum error correction (QEC) is used in quantum computing to protect quantum information from errors due to decoherence and other quantum noise. Quantum...
electron's state. Its values are natural numbers (from one) making it a discrete variable. Apart from the principal quantum number, the other quantum numbers...
fermions) cannot simultaneously occupy the same quantumstate within a system that obeys the laws of quantum mechanics. This principle was formulated by Austrian...
The quantum mind or quantum consciousness is a group of hypotheses proposing that local physical laws and interactions from classical mechanics or connections...
but not all, aspects of the quantum formalism are subjective in nature. For example, in this interpretation, a quantumstate is not an element of reality—instead...
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