In quantum mechanics, fractionalization is the phenomenon whereby the quasiparticles of a system cannot be constructed as combinations of its elementary constituents.
Many-body effects in complicated condensed materials lead to emergent properties that can be described as quasiparticles existing in the substance.
Electron behavior in solids can be considered as quasi-particle magnons, excitons, holes, and charges with different effective mass.
The most celebrated may be quantum Hall systems, occurring at high magnetic fields in 2D electron gas materials such as GaAs heterostructures.
Surface states in topological insulators of various compounds (e.g. tellurium alloys, antimony), and pure metal (bismuth) crystals[9] have been explored for fractionalization signatures.