In condensed matter physics, the spin–charge separation is an unusual behavior of electrons in some materials under some special conditions that allows the electrons to behave as a bound state of two independent particles, the spinon and the chargon, also known as the holon. The spinon only carries the spin of the electron but not the charge while the chargon/holon has spin equal to zero but its electric charge equals to the charge of the electron. Spin–charge separation is one of the most unusual manifestations of the concept of quasiparticles. This property is counterintuitive, because the "bare" quasiparticles are electrons, holes, phonons and photons, all of which have the property that bosons are evenly charged and fermions are oddly charged; and naively, it would seem that any quasip