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تسجيل مستخدم جديدCritical Behavior of Nuclear-Spin Diffusion in GaAs/AlGaAs Heterostructures near Landau Level Filling u=1
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Thermal measurements on a GaAs/AlGaAs heterostructure reveal that the state of the confined two-dimensional electrons dramatically affects the nuclear-spin diffusion near Landau level filling factor u=1. The experiments provide quantitative evidence that the sharp peak in the temperature dependence of heat capacity near u=1 is due to an enhanced nuclear-spin diffusion from the GaAs quantum wells into the AlGaAs barriers. We discuss the physical origin of this enhancement in terms the possible Skyrme solid-liquid phase transition.
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We have measured magnetic field dependences of the attenuation and velocity of surface acoustic waves in a high-mobility $n$-GaAs/AlGaAs structure with a wide quantum well. The results allowed us to find the complex conductance, $sigma(omega)$, of th
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Hyperfine interactions between electron and nuclear spins in the quantum Hall regime provide powerful means for manipulation and detection of nuclear spins. In this work we demonstrate that significant changes in nuclear spin polarization can be crea
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