Probing temperature-driven flow lines in a gated two-dimensional   electron gas with tunable spin-splitting
  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. 
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. Chan...
cond-mat.mes-hall cond-mat.dis-nn