Chiral current regulation and detection of Berry phase in triangular triple quantum dots

Abstract

Based on the hierarchical equations of motion (HEOM) calculation, we theoretically investigate the corresponding control of a triangular triple-quantum-dots (TTQD) ring which is connected to two reservoirs. We initially demonstrate by adding bias voltage and further adjusting the coupling strength between quantum dots, the chiral current induced by bias will go through a transformation of clockwise to counterclockwise direction and an unprecedented effective Hall angle will be triggered. The transformation is very rapid, with a corresponding characteristic time of 80–200 ps. In addition, by adding a magnetic flux to compensate for the chiral current in the original system, we elucidate the relationship between the applied magnetic flux and the Berry phase, which can realize direct measurement of the chiral current and reveal the magnetoelectric coupling relationship.