Single-qubit phase gates with two quantum dots embedded in T-type plasmonic waveguide

We have proposed several single-qubit phase gates with two quantum dots (QDs) embedded in a T-type plasmonic waveguides (PWs), wherein binary qubits are encoded by frequency of photons. Our results reveal that in such a hybrid system, an arbitrary single-qubit phase shift gates can be achieved and the gate performance could be controlled by adjusting spacing distance between two QDs and frequency detuning in a proper manner. We show that the phase of outstate can be adequately adjusted by distance between two QDs and the detuning could cause a phase shift. We investigated schemes theoretically via the real-space approach and estimated the feasibilities of them by evaluating fidelities for several parameters. Under the present technology and high fidelities, the proposed one could be utilized for quantum computation and quantum information processing.