Integer effects in the entanglement and spin fluctuations of a quantum   Hall system with Rashba interactions
  We report distinct nonanalytic signatures in the spin-orbit entanglement of a 2D electron gas with Rashba interactions at integer values of the filling factor and at certain level crossings. The accompanying sharp changes in the bulk spin-orbit entanglement entropy can be probed by measuring the fluctuation in the transverse spin polarization of the electron gas. 
Rona F. Barbarona, Francis N. C. Paraan
cond-mat.str-el cond-mat.mes-hall quant-ph