# Quantum Superposition

Quantum superposition is a fundamental principle of quantum mechanics that holds that a physical system—such as an electron—exists partly in all its particular, theoretically possible states (or, configuration of its properties) simultaneously; but, when measured or observed, it gives a result corresponding to only one of the possible configurations (as described in interpretation of quantum mechanics).

Mathematically, it refers to a property of solutions to the Schrödinger equation; since the Schrödinger equation is linear, any linear combination of solutions to a particular equation will also be a solution of it. Such solutions are often made to be orthogonal (i.e. the vectors are at right-angles to each other), such as the energy levels of an electron. By doing so the overlap energy of the states is nullified, and the expectation value of an operator (any superposition state) is the expectation value of the operator in the individual states, multiplied by the fraction of the superposition state that is "in" that state.

An example of a directly observable effect of superposition is interference peaks from an electron wave in a double-slit experiment. Another example is a pure quantum logical qubit state, as used in quantum information processing, which is a linear superposition of the "basis states" and .

### Other articles related to "quantum superposition, superposition, quantum, superpositions":

Quantum Superposition - Formal Interpretation
... Applying the superposition principle to a quantum mechanical particle, the configurations of the particle are all positions, so the superpositions make a complex wave in space ... The coefficients of the linear superposition are a wave which describes the particle as best as is possible, and whose amplitude interferes according to the ... For any physical property in quantum mechanics, there is a list of all the states where that property has some value ...
Superposition Principle - Application To Waves - Quantum Superposition
... In quantum mechanics, a principal task is to compute how a certain type of wave propagates and behaves ... approach to computing the behavior of a wavefunction is to write that wavefunction as a superposition (called "quantum superposition") of (possibly infinitely many) other wavefunctions of a certain type—stationary ... wavefunction can be computed through the superposition principle this way ...

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A personality is an indefinite quantum of traits which is subject to constant flux, change, and growth from the birth of the individual in the world to his death. A character, on the other hand, is a fixed and definite quantum of traits which, though it may be interpreted with slight differences from age to age and actor to actor, is nevertheless in its essentials forever fixed.
Hubert C. Heffner (1901–1985)