Incompressible quantum Hall fluid
= Incompressible quantum Hall fluid
An <incompressible quantum Hall fluid> has a bulk <spectral gap> against charged excitations; disorder can localize excess <quasiparticles>.<Anomalous Quantum Hall Effect: An Incompressible Quantum Fluid with Fractionally Charged Excitations by Robert Laughlin>[pp. 1397–1398, incompressibility and impurity localization]{ref}