Related papers: Goldstone mode stochastization in quantum Hall fer…
When Landau levels (LLs) become degenerate near the Fermi energy in the quantum Hall regime, interaction effects can drastically modify the electronic ground state. We study the quantum Hall ferromagnet formed in a two-dimensional hole gas…
We study intersubband spin density collective modes in double-layer quantum Hall systems at $\nu=2$ within the time-dependent Hartree-Fock approximation. We find that these intersubband spin density excitations may soften under…
We investigate the nu=1 quantum Hall ferromagnet in the presence of spin-orbit coupling of the Rashba or Dresselhaus type by means of Hartree-Fock-typed variational states. In the presence of Rashba (Dresselhaus) spin-orbit coupling the…
We exploit the influence of the Coulomb interaction between electrons and holes on the electron spin relaxation in a (110)-GaAs quantum well to unveil excitonic signatures within the many particle electron-hole system. The temperature…
We study the spin relaxation in an interacting two--dimensional electron gas in a strong magnetic field for the case that the electron density is close to filling just one Landau sub--level of one spin projection, i.e., for filling factor…
The double fractional quantum Hall system of spin 1/2 electrons is numerically studied to predict that there exists a novel spin-unpolarized quantum liquid specific to the multi-species system, which exemplifies a link between the spin…
We review some of the newest findings on the spin dynamics of carriers and excitons in GaAs/GaAlAs quantum wells. In intrinsic wells, where the optical properties are dominated by excitonic effects, we show that exciton-exciton interaction…
A coherent superposition of many nuclear spin states can be prepared and manipulated via the hyperfine interaction with the electronic spins by varying the Landau level filling factor through the gate voltage in appropriately designed…
The electron spin dynamics in (111)-oriented GaAs/AlGaAs quantum wells is studied by timeresolved photoluminescence spectroscopy. By applying an external field of 50 kV/cm a two-order of magnitude increase of the spin relaxation time can be…
In a low-disorder two-dimensional electron system, when two Landau levels of opposite spin or pseudospin cross at the Fermi level, the dominance of the exchange energy can lead to a ferromagnetic, quantum Hall ground state whose gap is…
We report a magnetotransport study of the termination of the spin-resolved integer quantum Hall effect by controlled disorder in a gated GaAs/AlGaAs heterostructure. We have found that, for a given N^{th} Landau level, the difference in…
An experimental technique for the indirect manipulation and detection of electron spins entangled in two-dimensional magnetoexcitons has been developed. The kinetics of the spin relaxation has been investigated. Photoexcited…
We study spin relaxation and dynamics of collective spin excitations in correlated double--exchange ferromagnets. For this, we introduce an expansion of the Green's functions equations of motion that treats non--perturbativerly all…
The tunneling conductance between two parallel 2D electron systems has been measured in a regime of strong interlayer Coulomb correlations. At total Landau level filling $\nu_T=1$ the tunnel spectrum changes qualitatively when the boundary…
Temperature and carrier density dependent spin dynamics for GaAs/AlGaAs quantum wells (QWs) with different structural symmetry has been studied by using time-resolved Kerr rotation technique. The spin relaxation time is measured to be much…
Time-dependent capacitance measurements reveal an unstable phase of electrons in gallium arsenide quantum well that occurs when two Landau levels with opposite spin are brought close to degeneracy by applying a gate voltage. This phase…
Recent experiments have demonstrated long spin lifetimes in uniformly n-doped quantum wells. The spin dynamics of exciton, localized, and conduction spins are important for understanding these systems. We explain experimental behavior by…
In wide GaAs quantum wells where two electric subbands are occupied we apply a parallel magnetic field or increase the electron density to cause a crossing of the two $N=0$ Landau levels of these subbands and with opposite spins. Near the…
We find unexpected low energy excitations of fully spin-polarized composite-fermion ferromagnets in the fractional quantum Hall liquid, resulting from a complex interplay between a topological order manifesting through new energy levels and…
We report on an absolute measurement of the electronic spin polarization of the $\nu=1$ integer quantum Hall state. The spin polarization is extracted in the vicinity of $\nu=1$ (including at exactly $\nu=1$) via resistive NMR experiments…