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 states. 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 quarks and gluons 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.