imported>WikiHarold: Repair Quantum Collection B backlink template

2026-05-08T19:52:42Z

Repair Quantum Collection B backlink template

← Older revision	Revision as of 19:52, 8 May 2026
(No difference)

imported>WikiHarold: Repair Quantum Collection B backlink template

2026-05-08T19:52:42Z

Repair Quantum Collection B backlink template

New page

{{DISPLAYTITLE:Quantum Superposition principle}}
{{Quantum book backlink|Wavefunctions and modes}}
'''Quantum superposition principle''' states that if a quantum system can be in one of two or more states, then any linear combination of those states is also a valid quantum state.<ref>[https://phys.libretexts.org/Workbench/Quantum_Mechanics_and_Quantum_Computation_%28Vazorani%29/01%3A_Introduction/1.03%3A_The_Superposition_Principle The Superposition Principle – Physics LibreTexts]</ref>
[[File:Quantum_superposition_light.svg|thumb|400px|Superposition of two quantum states forming a new state as a linear combination of wavefunctions.]]

== Mathematical formulation ==

If <math>\psi_1</math> and <math>\psi_2</math> are valid wavefunctions, then any linear combination

<math>\psi = c_1 \psi_1 + c_2 \psi_2</math>

is also a valid wavefunction, where:
* <math>c_1</math> and <math>c_2</math> are complex coefficients

For a normalized two-state system,

<math>|c_1|^2 + |c_2|^2 = 1</math>.<ref>[https://phys.libretexts.org/Bookshelves/Quantum_Mechanics/Advanced_Quantum_Mechanics_%28Kok%29/02%3A_The_Postulates_of_Quantum_Mechanics The Postulates of Quantum Mechanics – Physics LibreTexts]</ref>

== Physical interpretation ==

Superposition means that a system is described by a combination of possible states rather than a single definite classical state. In standard quantum mechanics, measurement is associated with probabilistic outcomes and state reduction.<ref>[https://plato.stanford.edu/archives/fall2004/entries/qm/ Quantum Mechanics – Stanford Encyclopedia of Philosophy]</ref>

== Interference effects ==

Superposition gives rise to interference phenomena:

* Constructive interference — amplitudes reinforce
* Destructive interference — amplitudes cancel

This is observed in wave and quantum experiments such as interference and wave-packet formation.<ref>[https://www.britannica.com/science/principle-of-superposition-wave-motion Principle of superposition – Britannica]</ref>

== Basis states and Hilbert space ==

Quantum states form a vector space (Hilbert space):
* States can be expressed in different bases
* Superposition depends on the chosen basis
* Eigenstates form a complete set

This vector-space structure is part of the standard postulates of quantum mechanics.<ref>[https://phys.libretexts.org/Bookshelves/Quantum_Mechanics/Advanced_Quantum_Mechanics_%28Kok%29/02%3A_The_Postulates_of_Quantum_Mechanics The Postulates of Quantum Mechanics – Physics LibreTexts]</ref>

== Applications ==

Superposition is central to modern quantum technologies:

* Quantum computing
* Quantum interference devices
* Atomic and optical physics

Britannica’s overview of quantum computing explicitly describes qubits as using superposition to hold multiple possible values at once.<ref>[https://www.britannica.com/technology/How-Do-Quantum-Computers-Work How Do Quantum Computers Work? – Britannica]</ref>

=See also=
{{#invoke:PhysicsQC|tocHeadingAndList|Physics:Quantum basics/See also}}

==References==
{{reflist|3}}
{{Author|Harold Foppele}}

{{Sourceattribution|Quantum Superposition principle|1}}

Physics:Quantum Superposition principle - Revision history

imported>WikiHarold: Repair Quantum Collection B backlink template

imported>WikiHarold: Repair Quantum Collection B backlink template