Electric manipulation of a valley qubit in a silicon quantum dot

In a silicon quantum dot, the valley states can be encoded as a qubit for quantum information processing. Here, we study theoretically the electric manipulation of valley qubit in a silicon quantum dot. The valley qubit frequency and electric manipulation speed are studied as a function of the location of interface steps and the applied electric field. We find that the applied electric field or the interface state can enhance the electric manipulation of the valley qubit. We further study the combined effect of QD confinement and interface steps on the electric manipulation of valley qubit. We will discuss the consequence of the results on the valley qubit based quantum information processing.