Physics:Quantum Spontaneous symmetry breaking: Difference between revisions

From HandWiki Test
Clean Short description prefix and add Book I label
Remove hidden BOM characters and direct Book label after Short description
Tag: Manual revert
Line 1: Line 1:
{{Short description|Selection of a less symmetric state from symmetric physical laws}}Book I
{{Short description|Selection of a less symmetric state from symmetric physical laws}}


{{ScholarlyWiki page top
{{ScholarlyWiki page top

Revision as of 11:04, 22 May 2026


← Previous : Field Theory Gauge symmetry
Next : Non-Abelian gauge theory →

Spontaneous symmetry breaking illustrated by a symmetric potential with asymmetric ground states.

Quantum spontaneous symmetry breaking occurs when the equations or energy function of a system have a symmetry, but the state chosen by the system does not display that full symmetry. The idea is central to condensed matter physics and quantum field theory.[1]

In many systems, the symmetric state is unstable or energetically disfavored. The system settles into one of several equivalent lower-energy states, each of which breaks the original symmetry in a particular direction.


Order and fields

A common picture is the Mexican-hat potential: the top is symmetric, but the stable ground states form a ring of choices. Once one point on the ring is selected, the symmetry is no longer visible in the realized state.

In quantum field theory, spontaneous symmetry breaking explains how fields can acquire nonzero vacuum values. In the electroweak theory, this idea is connected with the Higgs mechanism and the masses of weak gauge bosons.

Physical examples

Examples include magnetization in ferromagnets, crystal formation, superfluid phases, superconductivity, and the Higgs field. The broken symmetry often gives rise to collective modes, domain structures, or special low-energy excitations.

The concept helps explain how simple symmetric laws can produce structured and asymmetric physical worlds.

See also

References


Author: Harold Foppele


Source attribution: Physics:Quantum Spontaneous symmetry breaking