1209.0885 (Yi-Ting Wang et al.)

Probing temperature-driven flow lines in a gated two-dimensional
electron gas with tunable spin-splitting    [PDF]

Yi-Ting Wang, Gil-Ho Kim, C. F. Huang, Shun-Tsung Lo, Wei-Jen Chen, J. T. Nicholls, Li-Hung Lin, D. A. Ritchie, Y. H. Chang, C. -T. Liang, B. P. Dolan

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.

View original: http://arxiv.org/abs/1209.0885