We have detected oscillations of the charge around a potential hill (antidot) in a two-dimensional electron gas as a function of a perpendicular magnetic field B. The field confines electrons around the antidot in closed orbits, the areas of which are quantised through the Aharonov-Bohm effect. Increasing B reduces each state's area, pushing electrons closer to the centre, until enough charge builds up for an electron to tunnel out. This is a new form of the Coulomb blockade seen in electrostatically confined dots. We have also studied h/2e oscillations and found evidence for coupling of opposite spin states of the lowest Landau level.
@article{arxiv.cond-mat/9907467,
title = {Detection of Coulomb Charging around an Antidot},
author = {M. Kataoka and C. J. B. Ford and G. Faini and D. Mailly and M. Y. Simmons and D. R. Mace and C. -T. Liang and D. A. Ritchie},
journal= {arXiv preprint arXiv:cond-mat/9907467},
year = {2009}
}
Comments
3 pages, 3 Postscript figures, submitted to the proceedings of EP2DS-13