Quantum pumping and nuclear polarization in the integer quantum Hall regimeM. Blaauboer
Kavli Institute of NanoScience, Delft University of Technology Lorentzweg 1, 2628 CJ Delft, The Netherlands
received 19 July 2004; accepted in final form 3 November 2004
published online 8 December 2004
We study pumping of charge in a 2DEG in the quantum Hall regime at filling factor (2 spin-split levels of the lowest Landau level). For pumping frequencies that match the Zeeman energy splitting, quantum pumping together with hyperfine interaction between electrons and nuclei induces transitions between the spin-split levels. These lead to a step-like change in the pumped current and to polarization of the nuclei. We present quantitative predictions for both. Our model provides the first quantitative tool to both control and measure the amount of local nuclear polarization in a 2DEG.
72.20.-i - Conductivity phenomena in semiconductors and insulators.
73.43.-f - Quantum Hall effects.
72.25.Rb - Spin relaxation and scattering.
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