Premium
High‐Fidelity Universal Quantum Controlled Gates on Electron‐Spin Qubits in Quantum Dots Inside Single‐Sided Optical Microcavities
Author(s) -
Cao Cong,
Han YuHong,
Zhang Li,
Fan Ling,
Duan YuWen,
Zhang Ru
Publication year - 2019
Publication title -
advanced quantum technologies
Language(s) - English
Resource type - Journals
ISSN - 2511-9044
DOI - 10.1002/qute.201900081
Subject(s) - physics , qubit , quantum gate , quantum network , quantum error correction , quantum computer , quantum mechanics , cavity quantum electrodynamics , controlled not gate , quantum information , quantum dot , quantum circuit , quantum technology , photon , quantum information science , open quantum system , quantum , quantum entanglement
Semiconductor quantum‐dot (QD) spins hold great promise in quantum information science and technology. The implementation of high‐fidelity quantum gates on QD‐spin qubits is of great importance. Here, two schemes are presented to implement two universal quantum controlled gates, that is, the two‐qubit controlled‐not gate and the three‐qubit Toffoli gate, on stationary electron‐spin qubits in QDs inside single‐sided optical microcavities, based on the cavity‐assisted photon scattering under the balance condition. Compared with the previous schemes based on the ideal giant circular birefringence, the present schemes use the balance condition of the single‐sided QD‐cavity system, which can be achieved in both the weak‐ and strong‐coupling regimes of cavity quantum electrodynamics. Under the balance condition, the noise caused by the unbalanced reflectance between the coupled and uncoupled QD‐cavity systems can be efficiently depressed, so that the fidelity of each quantum gate operation can be increased to unity in principle. The schemes exhibit the possibility of realizing high‐fidelity and scalable quantum computing with single QD spins and single photons using the feasible and robust light–matter quantum interface. These high‐fidelity quantum controlled gates can lead to more efficient construction of quantum circuits for quantum computing, and provide a convenient avenue for quantum networking.