Deconfinement
Encyclopedia
In physics
, deconfinement (in contrast to confinement
) is the property of a phase in which certain particles are allowed to exist as free excitations
, rather than only within bound state
s. Various examples exist in particle physics
and condensed matter
, where certain gauge theories
exhibit transitions
between confining and deconfining phases.
A prominent example, and the first case considered as such in theoretical physics
, occurs at high energy in quantum chromodynamics
when quark
s and gluon
s are free to move over distances larger than a femtometer (the size of a hadron
). This phase is also called the quark-gluon plasma
.
Spin–charge separation is an example of deconfinement in condensed matter physics: the electron
can be viewed as a bound state of a 'spinon
' and 'chargon', which under certain conditions can become free to move separately.
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, deconfinement (in contrast to confinement
Confinement
Confinement may refer to either* Civil confinement for psychiatric patients* Color confinement, the physical principle explaining the non-observation of color charged particles like free quarks* Solitary confinement, a strict form of imprisonment...
) is the property of a phase in which certain particles are allowed to exist as free excitations
Excited state
Excitation is an elevation in energy level above an arbitrary baseline energy state. In physics there is a specific technical definition for energy level which is often associated with an atom being excited to an excited state....
, rather than only within bound state
Bound state
In physics, a bound state describes a system where a particle is subject to a potential such that the particle has a tendency to remain localised in one or more regions of space...
s. Various examples exist in particle physics
Particle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
and condensed matter
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
, where certain gauge theories
Gauge theory
In physics, gauge invariance is the property of a field theory in which different configurations of the underlying fundamental but unobservable fields result in identical observable quantities. A theory with such a property is called a gauge theory...
exhibit transitions
Phase transition
A phase transition is the transformation of a thermodynamic system from one phase or state of matter to another.A phase of a thermodynamic system and the states of matter have uniform physical properties....
between confining and deconfining phases.
A prominent example, and the first case considered as such in theoretical physics
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
, occurs at high energy in quantum chromodynamics
Quantum chromodynamics
In theoretical physics, quantum chromodynamics is a theory of the strong interaction , a fundamental force describing the interactions of the quarks and gluons making up hadrons . It is the study of the SU Yang–Mills theory of color-charged fermions...
when quark
Quark
A quark is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks are never directly...
s and gluon
Gluon
Gluons are elementary particles which act as the exchange particles for the color force between quarks, analogous to the exchange of photons in the electromagnetic force between two charged particles....
s are free to move over distances larger than a femtometer (the size of a hadron
Hadron
In particle physics, a hadron is a composite particle made of quarks held together by the strong force...
). This phase is also called the quark-gluon plasma
Quark-gluon plasma
A quark–gluon plasma or quark soup is a phase of quantum chromodynamics which exists at extremely high temperature and/or density. This phase consists of asymptotically free quarks and gluons, which are several of the basic building blocks of matter...
.
Spin–charge separation is an example of deconfinement in condensed matter physics: the electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
can be viewed as a bound state of a 'spinon
Spinon
Spinons are one of two quasiparticles, along with holons, that electrons in solids are able to split into during the process of spin–charge separation, when extremely tightly confined at temperatures close to absolute zero....
' and 'chargon', which under certain conditions can become free to move separately.
See also
- Quantum chromodynamicsQuantum chromodynamicsIn theoretical physics, quantum chromodynamics is a theory of the strong interaction , a fundamental force describing the interactions of the quarks and gluons making up hadrons . It is the study of the SU Yang–Mills theory of color-charged fermions...
- Colour confinementColour confinementColor confinement, often simply called confinement, is the physics phenomenon that color charged particles cannot be isolated singularly, and therefore cannot be directly observed. Quarks, by default, clump together to form groups, or hadrons. The two types of hadrons are the mesons and the baryons...
- Quark-gluon plasmaQuark-gluon plasmaA quark–gluon plasma or quark soup is a phase of quantum chromodynamics which exists at extremely high temperature and/or density. This phase consists of asymptotically free quarks and gluons, which are several of the basic building blocks of matter...
- Quark-novaQuark-novaA quark-nova is a hypothetical type of supernova that could occur if a neutron star spontaneously collapsed to become a quark star. The concept of quark-novae was suggested by Dr. Rachid Ouyed and Drs. Dey and Dey...