We study the temperature flow of conductivities in a gated GaAs two-dimensional electron gas (2DEG) containing self-assembled InAs dots and compare the results with recent theoretical predictions. By changing the gate voltage, we are able to tune the 2DEG density and thus vary disorder and spin-splitting. Data for both the spin-resolved and spin-degenerate phase transitions are presented, the former collapsing to the latter with decreasing gate voltage and/or decreasing spin-splitting. The experimental results support a recent theory, based on modular symmetry, which predicts how the critical Hall conductivity varies with spin-splitting.
@article{arxiv.1209.0885,
title = {Probing temperature-driven flow lines in a gated two-dimensional electron gas with tunable spin-splitting},
author = {Yi-Ting Wang and Gil-Ho Kim and C. F. Huang and Shun-Tsung Lo and Wei-Jen Chen and J. T. Nicholls and Li-Hung Lin and D. A. Ritchie and Y. H. Chang and C. -T. Liang and B. P. Dolan},
journal= {arXiv preprint arXiv:1209.0885},
year = {2012}
}