Quantum anti-dot formed with an airbridge gate in the quantum Hall regime

Abstract

We demonstrate a quantum antidot (QAD) formed with an airbridge gate on an AlGaAs/GaAs heterostructure, where a sub-micron pillar-shaped surface gate is biased via the bridge. We study transport through the QAD in the two regimes; one with a fully depleted region and the other with a partially depleted region at the center of the QAD. While standard Coulomb blockade (CB) oscillations with discrete levels are observed in the fully depleted region, short-period CB oscillations and more complicated patterns with multiple QADs are seen in the partially depleted region. The device is promising for investigating the few-particle regime.