量子测量中的信息擦除与量子印记及一阶SPAM误差分离
Information Erasure and Quantum Imprint in Quantum Measurement and First-Order SPAM Error Separation
- Institute of Science Tokyo（东京科学大学）
- The University of Osaka（大阪大学）
- Tohoku University（东北大学）
- Kumamoto University（熊本大学）
- Sigma-i Co., Ltd.（Sigma-i有限公司）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出信息擦除与量子印记两种性质对量子仪器分类，并证明信息擦除可在可靠后选择下实现SPAM误差的一阶分离，将问题转化为实现可靠后选择。
AI中文摘要：
我们引入信息擦除和量子印记作为对量子仪器进行分类的两个性质。信息擦除是指，通过适当的后选择，可以使早期测量结果的分布独立于初始量子态，同时保留所有结果分支。量子印记是互补性质，即任何可容许的后选择都无法消除这种状态依赖性。我们证明，这种分类具有非平凡的结构，并且关于测量提供更多初始量子态信息应更不可能展现信息擦除的自然直觉在一般情况下并不成立。我们进一步证明，在足够可靠的后选择下，信息擦除能够实现态制备和测量（SPAM）误差的一阶分离。具体而言，态制备误差的一阶贡献从后验分布中消失，而测量误差的可见一阶贡献仍然保留。这一结果将SPAM误差分离从同时表征态制备和测量的问题重新表述为实现可靠后选择的问题。
英文摘要：
We introduce information erasure and quantum imprint as two properties that classify quantum instruments. Information erasure is the property that an appropriate postselection can render the distribution of earlier measurement outcomes independent of the initial quantum state while retaining all outcome branches. Quantum imprint is the complementary property that no admissible postselection can eliminate this state dependence. We show that this classification has a nontrivial structure and that the natural intuition that measurements providing more information about the initial quantum state should be less likely to exhibit information erasure does not hold in general. We further show that, under a sufficiently reliable postselection, information erasure enables first-order separation of state-preparation and measurement (SPAM) errors. Specifically, the first-order contribution of state-preparation error vanishes from the posterior distribution, whereas visible first-order contributions of measurement error remain. This result recasts SPAM error separation from the problem of simultaneously characterizing state preparation and measurement into the problem of realizing a reliable postselection.
