AI 中文总结
研究在量子处理器上探测量子临界性下双自旋纠缠的问题，采用正偏置转置准则结合重叠态层析成像方法，在量子硬件上用变分电路制备量子临界态并绘制双自旋纠缠，为研究凝聚态系统提供了有效手段。
AI 中文摘要
多体系统中的量子相变会产生高度纠缠态，理解其量子关联对表征量子材料至关重要。然而，传统纠缠度量如纠缠熵难以解释噪声或混合态，且评估需复杂电路。因此，我们探索正偏置转置（PPT）准则与重叠态层析成像相结合，作为一种高效且可扩展的自旋 - 自旋纠缠见证。它能从约化密度矩阵中检测成对纠缠，区分量子与经典关联，适用于纯态和混合态。我们在量子硬件上演示了该方法，用变分电路制备多达20个量子比特的量子临界态，并完全绘制其在各种量子相变中的双自旋纠缠。
英文摘要
Quantum phase transitions in many-body systems give rise to highly entangled states, and understanding their quantum correlations is crucial for characterizing quantum materials. However, traditional entanglement measures such as entanglement entropy are difficult to interpret for noisy or mixed states and require complex circuits to evaluate. Therefore, we explore the Positive Partial Transpose (PPT) criterion, coupled with overlapping state tomography, as an efficient and scalable spin-spin entanglement witness. It detects pairwise entanglement from reduced density matrices, distinguishes quantum from classical correlations, and applies to both pure and mixed states. It is ideal for studying condensed matter systems prepared on noisy quantum devices as well as future extensions to finite temperatures. We demonstrate the approach on quantum hardware, using variational circuits to prepare quantum critical states with up to 20 qubits and completely map their two-spin entanglement across various quantum phase transitions.
