AI 中文总结
本研究提出结合自旋压缩动力学与量子信号处理的协议，用全连接两局域有界哈密顿量实现了$O(\log N/N)$时间、保真度$1-o(1)$的$N$比特GHZ编码，达到对应理论下界，经尺度变换也满足幂律相互作用哈密顿量的信号时间下界。
AI 中文摘要
我们证明，利用具有有界两比特相互作用项的全连接两局域哈密顿量，可在$O(\log N/N)$时间内完成保真度为$(1-o(1))$的$N$比特Greenberger–Horne–Zeilinger（GHZ，格林伯格-霍恩-蔡林格）态编码。该结果达到了理论下界$\Omega(\log N/N)$，经尺度变换后，也达到了$d$维中相互作用强度服从幂律$1/r^\gamma$（$\gamma<d$）的哈密顿量的信号传递时间下界。该协议结合了自旋压缩动力学与量子信号处理技术。
英文摘要
We prove that $(1-o(1))$-fidelity $N$-qubit Greenberger--Horne--Zeilinger (GHZ) encoding can be performed in time $O(\log N/N)$ using all-to-all 2-local Hamiltonians with bounded 2-qubit interaction terms. This saturates the theoretical lower bound $Ω(\log N/N)$, and by rescaling, also saturates the lower bound on signaling time for Hamiltonians with power-law interaction strengths $1/r^γ$, $γ<d$ in dimension $d$. The protocol uses spin-squeezing dynamics combined with quantum signal processing.
Comments23 pages, 3 figures
