The behavior of quantum cellular automata （QCA） under the influence of a stray charge is quantified. A new time-independent switching paradigm, a probability model of the double-dot system, is developed. Superiority...The behavior of quantum cellular automata （QCA） under the influence of a stray charge is quantified. A new time-independent switching paradigm, a probability model of the double-dot system, is developed. Superiority in releasing the calculation operation is presented by the probability model compared to previous stray charge analysis utilizing ICHA or full-basis calculation. Simulation results illustrate that there is a 186-nm-wide region surrounding a QCA wire where a stray charge will cause the target cell to switch unsuccessfully. The failure is exhibited by two new states＇ dominating the target cell. Therefore, a bistable saturation model is no longer applicable for stray charge analysis.展开更多
We present a scheme for implementing robust quantum gates in decoherence-free subspaces(DFSs) with double-dot spin qubits. Through the resonator-assisted interaction, the controllable interqubit couplings can be achie...We present a scheme for implementing robust quantum gates in decoherence-free subspaces(DFSs) with double-dot spin qubits. Through the resonator-assisted interaction, the controllable interqubit couplings can be achieved only by adjusting the qubit transition frequencies. We construct a set of logic gates on the DFS-encoded qubits to eliminate the collective noise effects, and thus the gate fidelities can be enhanced remarkably. This proposal may offer a potential approach to realize the robust quantum computing with spin qubits.展开更多
基金supported by the National Natural Science Foundation of China(No.61172043)the Key Program of Shaanxi Provincial Natural Science for Basic Research(No.2011JZ015)
文摘The behavior of quantum cellular automata （QCA） under the influence of a stray charge is quantified. A new time-independent switching paradigm, a probability model of the double-dot system, is developed. Superiority in releasing the calculation operation is presented by the probability model compared to previous stray charge analysis utilizing ICHA or full-basis calculation. Simulation results illustrate that there is a 186-nm-wide region surrounding a QCA wire where a stray charge will cause the target cell to switch unsuccessfully. The failure is exhibited by two new states＇ dominating the target cell. Therefore, a bistable saturation model is no longer applicable for stray charge analysis.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11047006,11304267Programs for Science and Technology Innovation Talents in Universities of Henan Province under Grant No.13HASTIT049+2 种基金Young Backbone Teachers in Universities of Henan Province under Grant No.2012GGJS-173Prominent Young Backbone Talents of Xuchang Universitythe Natural Science Foundation of Zhejiang Province under Grant No.Y6110250
文摘We present a scheme for implementing robust quantum gates in decoherence-free subspaces(DFSs) with double-dot spin qubits. Through the resonator-assisted interaction, the controllable interqubit couplings can be achieved only by adjusting the qubit transition frequencies. We construct a set of logic gates on the DFS-encoded qubits to eliminate the collective noise effects, and thus the gate fidelities can be enhanced remarkably. This proposal may offer a potential approach to realize the robust quantum computing with spin qubits.
