论文标题
量子块lookahead加法器和等待魔术状态
Quantum block lookahead adders and the wait for magic states
论文作者
论文摘要
我们改善了低深度量子添加器的toffoli数量，并分析了他们的时空成本对有限数量的魔术状态工厂的反应。我们提出一个lookahead加法器，该加法器在大小$ b $的位块中并行，而不是在所有位上。 Block LookAhead Adder获得了$ 3N + 5n/b $的Toffoli计数，以增加额外的额外（Thapliyal等人的先前工作中的$ 4N $），而$ 5N + 8n/b $ for Addage（Thapliyal等人在Thapliyal等工作中的$ 7N $）。权衡的是，这些电路的反应深度在$ b $上线性依赖，并且它们使用了其他工作空间。我们根据表面代码和超导量子的大规模量子计算机的各种寄存器尺寸和工厂计数估算了这些加法器的时空音量以及以前工作的添加剂，并估计了各种寄存器尺寸和工厂计数。
We improve the Toffoli count of low depth quantum adders, and analyze how their spacetime cost reacts to having a limited number of magic state factories. We present a block lookahead adder that parallelizes across blocks of bits of size $b$, instead of over all bits. The block lookahead adder achieves a Toffoli count of $3n + 5n/b$ for out of place addition (vs $4n$ in previous work by Thapliyal et al) and $5n + 8n/b$ for in place addition (vs $7n$ in previous work by Thapliyal et al). The tradeoff is that the reaction depth of these circuits depends linearly on $b$, and they use additional workspace. We estimate the spacetime volume of these adders, and adders from previous work, for various register sizes and factory counts under plausible assumptions for a large scale quantum computer based on the surface code and superconducting qubits.
