We have studied the development of metastable properties associated with a nearly spin-degenerate two-dimensional electron system. Application of large hydrostatic pressure significantly reduces the g-factor experienced by electrons in GaAs/AlGaAs heterostructure, and various fractional quantum Hall effect (FQHE) states are found to undergo transition to a spin-unpolarized ground state. In case of even numerator FQHE states, the spin transitions are accompanied by hysteresis and nonlinearity in the magnetotransport. These results strongly support a recent theory of quantum Hall magnetism in which competition between spin-polarized and spin-unpolarized ground states leads to an ordered phase that exhibits ferromagnetic correlation.
Cho, H., Kang, W., Campman, K. L., Gossard, A. C., Bichler, M., & Wegscheider, W. (2000). Hysteresis, spin transitions, and magnetic ordering in the fractional quantum Hall effect. Physica E: Low-Dimensional Systems and Nanostructures, 6(1), 18–21. https://doi.org/10.1016/S1386-9477(99)00045-4