Majorana fermion

In <a href="/facts/Particle_physics/YgIuyj2t">particle physics</a> a Majorana fermion or Majorana particle is a <a href="/facts/Fermion/LEckdDsR">fermion</a> that is its own <a href="/facts/Antiparticle/7Ic43ThI">antiparticle</a>. They were hypothesised by <a href="/facts/Ettore_Majorana/3SzGKHSx">Ettore Majorana</a> in 1937. The term is sometimes used in opposition to <a href="/facts/Dirac_fermion/gJuu9J69">Dirac fermion</a>, which describes fermions that are not their own antiparticles.
With the exception of <a href="/facts/Neutrino/yGWVfSg2">neutrinos</a>, all of the <a href="/facts/Standard_Model/LhVGf9ow">Standard Model</a> elementary fermions are known to behave as Dirac fermions at low energy (lower than the <a href="/facts/Electroweak_symmetry_breaking/Vs5Cbxyy">electroweak symmetry breaking</a> temperature), and none are Majorana fermions. The nature of neutrinos is not settled – they may be either Dirac or Majorana fermions.
In <a href="/facts/Condensed_matter_physics/EBVI5nmL">condensed matter physics</a>, <a href="/facts/Quasiparticle/Bpx2MNpb">quasiparticle</a> <a href="/facts/Excited_state/czcLYNnr">excitations</a> can appear like bound Majorana states. However, instead of a single <a href="/facts/Fundamental_particle/CTFDM97U">fundamental particle</a>, they are the collective movement of several individual particles (themselves composite) which are governed by <a href="/facts/Anyon/hfgpCFjf">non-Abelian statistics</a>.

Majorana fermion open-in-new

Majorana fermion