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Composite Boson
A composite boson is a bound state of fermions such that the combination gives a boson.Monique Combescot and Shiue-Yuan Shiau, "Excitons and Cooper Pairs: Two Composite Bosons in Many-Body Physics", Oxford University Press (). Examples include Cooper pairs, semiconductor excitons, mesons, superfluid helium, Bose–Einstein condensates, atomic bosons, and fermionic condensates. A composite particle containing an even number of fermions is a boson, since it has integer spin. These composite particle states have a symmetric wave function upon exchange of any pair of particles. The wave function is given by the permanent of single particle states for the non interacting case. See also * Composite fermion References * University of Colorado (January 28, 2004). ''NIST/University of Colorado Scientists Create New Form of Matter: A Fermionic Condensate''. Press Release. * Rodgers, Peter & Dumé, Bell (January 28, 2004). ''Fermionic condensate makes its debut''. PhysicWeb. * Haegler, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermion
In particle physics, a fermion is a particle that follows Fermi–Dirac statistics. Generally, it has a half-odd-integer spin: spin , spin , etc. In addition, these particles obey the Pauli exclusion principle. Fermions include all quarks and leptons and all composite particles made of an odd number of these, such as all baryons and many atoms and nuclei. Fermions differ from bosons, which obey Bose–Einstein statistics. Some fermions are elementary particles (such as electrons), and some are composite particles (such as protons). For example, according to the spin-statistics theorem in relativistic quantum field theory, particles with integer spin are bosons. In contrast, particles with half-integer spin are fermions. In addition to the spin characteristic, fermions have another specific property: they possess conserved baryon or lepton quantum numbers. Therefore, what is usually referred to as the spin-statistics relation is, in fact, a spin statistics-quantum numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
