 Compressible quantum Hall edge strip

A compressible quantum Hall edge strip is an edge region where a Landau level is partly occupied and nearby states permit the local electron density to adjust. This adjustment screens the confining field and tends to flatten the effective energy of that level near the chemical potential.

It contrasts with an incompressible quantum Hall edge strip, where a gap suppresses the corresponding density response. Their alternating arrangement is a self-consistent property of electrons and the confining electrostatics, rather than simply a drawing of unperturbed levels through a fixed potential. Finite temperature, disorder and interactions can modify the ideal strip structure.^[ref]