High-fidelity quantum gates on quantum-dot-confined electron spins in low-Q optical microcavities

Research paper by Tao Li, Jian-Cun Gao; Fu-Guo Deng; Gui-Lu Long

Indexed on: 03 Mar '18Published on: 25 Feb '18Published in: Annals of Physics


Publication date: Available online 19 February 2018 Source:Annals of Physics Author(s): Tao Li, Jian-Cun Gao, Fu-Guo Deng, Gui-Lu Long We propose some high-fidelity quantum circuits for quantum computing on electron spins of quantum dots (QD) embedded in low-Q optical microcavities, including the two-qubit controlled-NOT gate and the multiple-target-qubit controlled-NOT gate. The fidelities of both quantum gates can, in principle, be robust to imperfections involved in a practical input–output process of a single photon by converting the infidelity into a heralded error. Furthermore, the influence of two different decay channels is detailed. By decreasing the quality factor of the present microcavity, we can largely increase the efficiencies of these quantum gates while their high fidelities remain unaffected. This proposal also has another advantage regarding its experimental feasibility, in that both quantum gates can work faithfully even when the QD-cavity systems are non-identical, which is of particular importance in current semiconductor QD technology.