Theory of electronic transport through a triple quantum dot in the presence of magnetic field

A theory of electronic transport through an empty triangular triple quantum dot subject to a perpendicular magnetic field is developed using a tight-binding model and Landauer-Buttiker approach. We show that a magnetic field allows one to engineer degeneracies in the energy spectrum of the triple quantum dot. The degeneracies lead to zero electronic transmission and sharp dips in the current whenever a pair of degenerate states lies between the chemical potentials of the two leads. These dips can occur with a periodicity of one flux quantum if only two levels contribute to the current or with half a flux quantum if the three levels of the triple dot contribute. The effect of strong bias voltage and different lead-to-dot connections on Aharonov-Bohm oscillations in the conductance is also discussed.