Magnetospectroscopy of 2D Electron Gas: Cusps in Emission Spectra and Coulomb Gaps
Apal'kov V.M., Rashba E.I.
A theory of photoluminescence due to radiative trapping of 2D electrons from a confinement layer on neutral impurity centers is presented. In the dependence of the emission band position on the filling factor ν there are cusps at fractional values ν — p/q, these cusps are closely connected to cusps in the ground state energy of interacting 2D electrons; the latter cusps arising due to formation of incompressible liquids at these points. The effect of the finite state interaction on the cusp shape is investigated, and the possibility for determining Coulomb gaps from cusp strengths is discussed.