Deterministic quantum logic gates and quantum cloning based on quantum dot-cavity coupled system

We propose two theoretical schemes for creating the CNOT gate and Toffoli gate deterministically by using the singly charged quantum dots inside the double-sided microcavities. Both of the two schemes only need one photon to act as an ancilla. A high fidelity can be achieved in the strong coupling regime. Finally, a quantum cloning machine is constructed theoretically to copy a quantum state near a given state by using the CNOT gate and the Toffoli gate, which simplifies the implementation of quantum cloning compared with previous proposals.