Anderson localization 2026-10-18
Anderson localization is the confinement of Electron wave functions, or other wave modes, by interference between repeated wave scattering paths in static disorder. A localized eigenstate occupies a limited region even in a much larger sample. Disorder can therefore suppress diffusion without absorbing the wave. In 1958, Philip Warren Anderson studied random site energies and intersite coupling, finding a regime without transport. His paper develops a theoretical model; it does not report an Anderson laboratory measurement.[ref]
The distinction from ordinary multiple scattering is the retention of wave phases: alternative paths contribute probability amplitudes before their squared modulus is taken. Adding path probabilities alone loses the cross terms responsible for interference. This makes Anderson localization useful as a warning about transport models: repeated deflections need not produce unlimited diffusion. It also connects Electron transport with wave propagation in a random medium, although the detailed equations and experimental diagnostics differ between Electrons, light and acoustic waves.
Philip Warren Anderson's 1977 lecture distinguishes localized magnetic moments from disorder-localized states. It credits Nevill Francis Mott with recognizing the significance of the mobility edge. A Mott insulator instead requires Electron interactions and can exist without disorder.[ref]
John Hasbrouck Van Vleck developed quantum mechanics explanations of magnetic susceptibility, including its temperature dependence; this is a distinct contribution from Anderson localization.[ref]
Awarded in equal shares to Philip Warren Anderson, Nevill Francis Mott and John Hasbrouck Van Vleck for theoretical investigations of electronic structure in magnetic and disordered systems.[ref]
In his 1985 recollection, Sam Edwards traced his work with Philip Warren Anderson to Saturday discussions and an analogy with randomly crosslinked polymers. He adapted methods from rubber theory during train journeys while chairing the Science Research Council.[ref]