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

[摘要] We have studied the magnetoconductance of quantum dots with triangular symmetry and areas down to 0.2 mu m(2), made in a high mobility two-dimensional electron gas embedded in a GaAs-AlxGa1-xAs 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.

[关键词] WEAK MAGNETIC-FIELDS;CONDUCTANCE FLUCTUATIONS;PHASE BREAKING;CHAOTIC SCATTERING;TRANSPORT;TRANSITION;BILLIARDS;CAVITIES;ORBITS;SHAPE