Band-gap renormalization and photoluminescence from an interacting two-dimensional electron gas in a magnetic field

The renormalization of the band gap due to e–e interaction and its effect on photoluminescence in an interacting two-dimensional electron gas in a magnetic field is discussed. From the calculation of the Hartree–Fock quasi-particle energy at even filling factors we show that the band gap has a linear dependence on the magnetic field B up to filling factor 2, where the dependence changes to that dominated by the square root of B. At odd filling factors the breakdown of the quasi-particle leads to anomalies in the band gap. These anomalies vanish when temperature exceeds Zeeman energy. At these temperatures the View the MathML source dependence is recovered at lower even filling factors e.g.4. These predictions are compared with magneto-luminescence experiments on CdTe modulation doped quantum wells.