Kukushkin, I. V. and Falko, Vladimir and Haug, R. J. and von Klitzing, K. and Eberl, K. (1996) Magneto-optical evidence of the percolation nature of the metal-insulator transition in the two-dimensional electron system. Physical review B, 53 (20). pp. 13260-13263. ISSN 0163-1829
Abstract
We compare the results of the transport and time-resolved magnetoluminescence measurements in disordered two-dimensional (2D) electron systems in GaAs-AlxGa1-xAs heterostructures in the extreme quantum limit, particularly in the vicinity of the metal-insulator transition (MIT). At filling factors nu<1, the optical signal has two components: the single-rate exponentially decaying part attributed to a uniform liquid and a power-law long-living tail specific to a microscopically inhomogeneous state of electrons. We interpret this result as a separation of the 2D electron system into liquid and localized phases, especially because the MIT occurs strikingly close to those filling factors where the liquid occupies 1/2 of the sample area (the percolation threshold condition in two-component media).