Integer Quantum Hall Effect

Discovery that Hall conductance in a 2D electron gas is quantized in exact integer multiples of e^2/h, independent of sample geometry or purity (von Klitzing, Dorda & Pepper, 1980) -- the first quantum Hall effect found, later explained topologically (Laughlin 1981, TKNN 1982) and distinct from the Fractional QHE discovered two years later. Query term required the "integer quantum hall effect" exact phrase; the bare "quantum hall effect" term does not separate this from the fractional variant and picks up unrelated noise. Von Klitzing won the 1985 Nobel Prize.