Electrical switching of the edge channel transport in HgTe quantum wells with an inverted band structure

We demonstrate theoretically an electrical switching of the edge-state transport by means of a quantum point contact in HgTe quantum wells with an inverted band structure. The switch-on/off of the edge channel is caused by the finite size effect of the quantum point contact and therefore can be manipulated by tuning the voltage applied on the split gate. This electrical switching behavior offers us an efficient way to control the topological edge state transport which is robust against the local perturbation.