Stabilization of single-electron pumps by high magnetic fields

J. D. Fletcher, M. Kataoka, S. P. Giblin, Sunghun Park, H. -S. Sim, P. See, T. J. B. M. Janssen, J. P. Griffiths, G. A. C. Jones, H. E. Beere, D. A. Ritchie

Published 2011-07-22, updated 2012-08-31Version 3

We study the effect of perpendicular magnetic fields on a single-electron system with a strongly time-dependent electrostatic potential. Continuous improvements to the current quantization in these electron pumps are revealed by high-resolution measurements. Simulations show that the sensitivity of tunnel rates to the barrier potential is enhanced, stabilizing particular charge states. Nonadiabatic excitations are also suppressed due to a reduced sensitivity of the Fock-Darwin states to electrostatic potential. The combination of these effects leads to significantly more accurate current quantization.