fractional quantum Hall effect

The fractional quantum Hall effect is a phenomenon observed in two-dimensional electron systems at extremely low temperatures and under strong magnetic fields. It's an extension of the quantum Hall effect, where the Hall resistance changes in discrete steps proportional to integers. In the fractional version, these changes occur in fractional increments, suggesting that the charge carriers possess fractions of an electron's charge.12

Physicist Robert B. Laughlin explained this by proposing that electrons form a "quantum fluid" under these extreme conditions. In this fluid, quasi-particles with fractional electric charges emerge. This discovery, made by Laughlin, Daniel C. Tsui, and Horst L. Störmer, earned them the Nobel Prize in Physics in 1998. The Hall effect itself, discovered by Edwin Herbert Hall in 1879, involves the development of an electric field in a current-carrying material when placed in a perpendicular magnetic field.123