Anti-bias voltage electron-Kondo transport in a quantum dot device driven by a graphene sheet

•We propose a scheme to enhance the anti-bias voltage capability of the Kondo resonance in a quantum dot device.•A high-differential conductance electron channel is opened up in a quantum dot device by a graphene sheet.•A conductance/current regulating valve is realized in a quantum dot device by a graphene sheet.

We theoretically investigate the manipulation of electron-Kondo transport through a single-quantum dot (QD) two-electrode device by introducing a side-coupled graphene sheet. It is shown that with increase of coupling strength between the QD and the zero-potential graphene sheet, the anti-bias voltage capability of the QD–electrode Kondo resonance is improved obviously. This causes a high-conductance QD–electrode channel to be opened up for electron transport within a wide bias voltage range. Moreover, the conductance/current of the Kondo channel can be accurately controlled by adjusting the potential of the graphene sheet. These results may be useful for the observation of nonequilibrium Kondo effect and the design of high-conductance control device.