Abstract We introduce an enhanced technique for strong classical simulation of quantum circuits which combines the `sum-of-stabilisers' method with an automated simplification strategy based on the ZX-calculus. Recently it was shown that quantum circuits can be classically simulated by expressing the non-stabiliser gates in a circuit as magic state injections and decomposing them in chunks of 2-6 states at a time, obtaining sums of (efficiently-simulable) stabiliser states with many fewer terms than the naive approach. We adapt these techniques from the original setting of Clifford circuits with magic state injection to generic ZX-diagrams and show that, by interleaving this ``chunked'' decomposition with a ZX-calculus-based simplification strategy, we can obtain stabiliser decompositions that are many orders of magnitude smaller than existing approaches. We illustrate this technique to perform exact norm calculations (and hence strong simulation) on the outputs of random 50- and 100-qubit Clifford+T circuits with up to 70 T-gates as well as a family of hidden shift circuits previously considered by Bravyi and Gosset with over 1000 T-gates.

中文翻译：

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用 ZX 演算模拟量子电路减少了稳定器分解

摘要 我们介绍了一种增强的技术，用于对量子电路进行强经典模拟，该技术将“稳定器总和”方法与基于 ZX 演算的自动简化策略相结合。最近表明，量子电路可以通过将电路中的非稳定器门表示为魔术状态注入并一次将它们分解为 2-6 个状态的块来进行经典模拟，从而获得（有效模拟的）稳定器状态的总和比天真的方法少很多术语。我们将这些技术从具有魔术状态注入的 Clifford 电路的原始设置改编为通用 ZX 图，并表明，通过将这种“分块”分解与基于 ZX 演算的简化策略交错，我们可以获得比现有方法小许多数量级的稳定器分解。我们说明了这种技术，以对具有多达 70 个 T 门的随机 50 和 100 量子比特 Clifford+T 电路以及 Bravyi 先前考虑的一系列隐藏移位电路的输出执行精确的范数计算（并因此进行强大的模拟）和 Gosset 有超过 1000 个 T 型门。