Abstract
We discuss the current state of knowledge concerning the three following questions : i) what is the physical system most appropriate for the observation of the Wigner transition in an electron plasma ? ii) how such a system can be optimized in order to limit competing effects like single-particle localization ? iii) which experimental techniques allow unambiguous observation of this transition ? We present the results concerning our study of dense quantum two-dimensional electron systems in low disordered selectively doped GaAs/GaAIAs heterojunctions and our evidences for a magnetically induced Wigner transition obtained concomitantly by resonant absorption of radio-frequency waves and by voltage-source transport measurements at low temperature and high magnetic field.