Periodic magnetoconductance fluctuations in triangular quantum dots in the absence of selective probing

TL;DR

This study investigates magnetoconductance oscillations in triangular quantum dots, revealing ballistic effects and Aharonov-Bohm flux quantization linked to classical triangular orbits, despite the orbit's inaccessibility via classical trajectories.

Contribution

It demonstrates the presence of Aharonov-Bohm oscillations in triangular quantum dots without selective probing, linking them to classical triangular orbits through combined experimental and theoretical analysis.

Findings

Periodic oscillations observed below 1 K

Oscillations explained by flux quantization of classical triangular orbit

Classical orbit not accessible by collimated beam trajectories

Abstract

We have studied the magnetoconductance of quantum dots with triangular symmetry and areas down to 0.2 square microns, made in a high mobility two-dimensional electron gas embedded in a GaAs-AlGaAs heterostructure. Semiclassical simulations show that the gross features in the measured magnetoconductance are caused by ballistic effects. Below 1 K we observe a strong periodic oscillation, which may be explained in terms of the Aharanov-Bohm flux quantization through the area of a single classical periodic orbit. From a numerical and analytical analysis of possible trajectories in hard- and soft-walled potentials, we identify this periodic orbit as the enscribed triangle. Contrary to other recent experiments, this orbit is not accessible by classical processes for the incoming collimated beam.