Quantitative examination of the collapse of spin splitting in the quantum Hall regime

We have quantitatively tested the theoretical model on the collapse of spin slitting in the quantum Hall effect regime proposed by Fogler and Shklovskii in a high-mobility two-dimensional electron system (2DES) realized in a heterojunction insulated-gate field-effect transistor. In the 2DES density range between n = 2 × 1010 and 2 × 1011 cm^-2, the Landau level number N displays a power-law dependence on the critical electron density n_c where the spin splitting collapses and N = 11.47 × n _c0.64^±0.01 (n_c is in units of 1011 cm^-2). This power-law dependence is in good agreement with the theoretical prediction in the low-density regime.