Thermoelectric Efficiency Enhanced by Fano Interference in a Quantum Anomalous Hall Insulator Quantum Dot

Thermoelectric properties of a quantum dot (QD) connected to two metal leads are studied, where the QD is fabricated by the quantum anomalous Hall insulator. Surface states emerge at the edge of the QD due to the bulk-boundary correspondence, while bulk states spread over the whole QD. Fano interference will occur between tunneling via surface and bulk states, which leads to asymmetric lineshape and minimum in the transmission and electric conductance spectrums. Both Seebeck coefficient and thermoelectric figure of merit are enhanced greatly in the energy regime of Fano interference. In addition, it is shown that Fano interference and thermoelectric properties can be well tuned by magnetic field.