Cho, Hyun-Ick and Kang, W. and Campman, K. L. and Gossard, A. C. and Bichler, Max and Wegscheider, Werner
Hysteresis, spin transitions, and magnetic ordering in the fractional quantum Hall effect.
Physica E Low-dimensional Systems and Nanostructures 6 (1-4), pp. 18-21.
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.