We study the quantum Hall liquid and the metal-insulator transition in a high mobility two dimensional electron gas, by means of photoluminescence and magneto-transport. In the integer and fractional regime at nu > 1/3, analyzing the emission energy dispersion we probe the magneto-Coulomb screening and the hidden symmetry of the electron liquid. In the fractional regime above above nu =1/3 the system undergoes the metal-to-insulator transition, and in the insulating phase the dispersion becomes linear with evidence of an increased renormalized mass.
@article{arxiv.1007.2936,
title = {Optical probing of correlation driven liquid-to-insulator transition in 2D electron gas},
author = {F. Dionigi and F. Rossella and V. Bellani and M. Amado and E. Diez and K. Kowalik and G. Biasiol and L. Sorba},
journal= {arXiv preprint arXiv:1007.2936},
year = {2011}
}