Commensurability Effects in Hexagonal Antidot Lattices with Large Antidot Diameters

TL;DR

This paper reports a new type of classical commensurability resonance in large-diameter hexagonal antidot lattices, caused by quasi-stable electron trajectories, with experimental and simulation evidence supporting the findings.

Contribution

It introduces a novel classical resonance phenomenon in antidot lattices with large antidots, supported by experimental observations and simulations.

Findings

Resonances occur at magnetic fields above the single-antidot resonance.

Resonances are observed only for antidots larger than 50% of the lattice constant.

Large-period Aharonov-Bohm oscillations are detected at low temperatures.

Abstract

The observation of a novel type of commensurability resonance in two-dimensional, hexagonal antidot lattices is reported. These resonances have a classical character and occur at magnetic fields above the resonance that corresponds to the cyclotron motion around a single antidot. The resonances are visible only for antidots with effective diameters larger than 50 % of the lattice constant. Simulations reveal that they originate from quasi-stable electron trajectories that bounce between three neighboring antidots. This interpretation is backed by the observation of large-period Aharonov-Bohm type oscillations at low temperatures.