Probing spin physics in the quantum Hall regime by heat capacity and magnetotransport measurements

We review recent heat capacity and magnetotransport experiments on <f>GaAs/AlGaAs</f> heterostructures containing multilayer two-dimensional electron systems (2DESs) in the quantum Hall regime. Emphasis in this article is on the study of the heat capacity near Landau level filling factor <f>ν=1</f>. We also present a detailed survey of the development of the quantum Hall effect in tilted-magnetic fields for <f>ν&lsim;2</f>. Among the novel phenomena we address is the strong coupling between the nuclear spins and the electrons associated with the spin phase transitions of the 2DES at <f>ν=4/3</f> and near <f>ν=1</f>. To cite this article: S. Melinte et al., C. R. Physique 3 (2002) 667–676. [Copyright &y& Elsevier]