Under special conditions of very high density and low temperatures (micro-kelvin), electrons can be reduced into three components quasiparticles. The spinon carries electron spin, while the orbiton carries orbital location and the holon carries charge. The spin-charge separation process results in the quasiparticles acting as separate entities. This means that the once fundamental member of Particle Zoo is not really indivisible. How far does the rabbit hole actually go?
This property of the electron is an addendum. Although it was first hypothesized in 1960’s, it was not observed until 2006 at University of Berkeley. You can find many articles online if you search the keywords spin-charge separation or spinon, orbiton or holon.