AI 中文总结
研究利用光谱噪声量子发射器实现可扩展光子介导双量子比特门的问题，提出最优腔辅助门协议（POCEG），通过不同策略克服量子比特光谱差异，实现高保真，使双量子比特门跨越容错量子计算阈值。
AI 中文摘要
当两个量子比特通过腔耦合时，可在近共振或色散 regime 实现双量子比特门。但当量子比特存在光谱噪声或与腔失谐不同时，操作保真度会大幅降低，阻碍可扩展实现。我们引入最优腔辅助门协议（POCEG），通过可靠数值和解析解，克服量子比特间光谱差异，在不同/噪声量子发射器间实现高保真。对于低阻尼率腔，在腔频率对量子比特施加脉冲序列并周期性调制耦合；高阻尼率时，在远离腔频率处施加脉冲。两种情况在适度脉冲间延迟下，可将因量子比特光谱失配而强烈抑制的保真度提高到 99.9%以上，该协议能使固态系统间的双量子比特门跨越容错量子计算所需阈值。
英文摘要
When two quantum bits are coupled through a cavity, a two-qubit gate can be realized between them either in the near-resonant regime over a timescale established by the coupling strength of the qubits with the cavity, or in the dispersive regime, over a longer timescale established by the combination of the coupling strength and the frequency detuning between the qubits and the cavity. When the qubits are spectrally noisy or differently detuned from the cavity, the fidelity for the operation can be drastically reduced in either case, precluding scalable realizations. We introduce the protocol for optimal cavity-enabled gates (POCEG) that is shown, through reliable numerical and analytical solutions, to overcome spectral differences between quantum bits and to achieve high fidelity between disparate/noisy quantum emitters. Namely, for a cavity with low damping rate, we apply a sequence of pulses to the qubits at the frequency of the cavity while periodically modulating the coupling of the qubits to the cavity. Alternatively, in the case of a large damping rate, we operate in the dispersive regime and overcome spectral disparities by applying the pulses at a frequency far-detuned from the cavity. In both instances, we find for the quantum state transfer between the two qubits that, with a modest inter-pulse delay, the fidelity that would otherwise be strongly suppressed by the spectral mismatch of the qubits can be increased beyond 99.9%. These protocols have the capacity to bring two-qubit gates between solid state systems across the threshold required for fault-tolerant quantum computing.
Comments15 pages, 7 figures
