AI 中文总结
研究通过浅变分量子电路检测量子相变，利用变分量子本征求解器的Delta-VQE方法，经对含三自旋团簇相互作用的一维横场伊辛模型研究发现，其诊断能力依赖于合理选择有物理代表性的近似，能高效探测量子临界性。
AI 中文摘要
通过经典模拟绘制量子相图资源消耗极大，即便远离热力学极限的小系统也需巨大计算量。变分量子本征求解器（VQE）提供了替代方案，利用近似基态区分相。一种名为Delta-VQE的方法通过对比不同相参考态优化的变分能量确定临界点，电路深度降低时诊断更精确。本文研究含三自旋团簇相互作用的一维横场伊辛模型，发现采用对偶近似时Delta-VQE总检测到自对偶点而非真正临界点，精心定制近似可成功识别真正伊辛临界点且有限尺寸效应小。结果表明Delta-VQE虽能高效探测量子临界性，但诊断能力取决于合理选择有物理代表性的近似。
英文摘要
Mapping quantum phase diagrams through classical simulation is notoriously resource-intensive, as even small systems far from the thermodynamic limit demand prohibitive computational effort. The variational quantum eigensolver (VQE) offers a compelling alternative, exploiting approximate ground states to distinguish phases. An appealing proposal, dubbed as Delta-VQE, determines critical points by contrasting variational energies optimized from reference states of distinct phases. Intriguingly, the diagnostic sharpens as circuit depth decreases, highlighting its promise as a resource-conscious probe of quantum criticality. To probe the broader applicability and underlying mechanisms of this approach, we investigate the one-dimensional transverse-field Ising model with a three-spin cluster interaction, a setting in which the Ising transitions are generally situated beyond the self-dual line. We demonstrate that, whenever dual ansätze are employed, Delta-VQE invariably detects the self-dual points rather than the true criticality. In contrast, when ansätze are carefully tailored to embody the competing phases across the boundary, the genuine Ising critical point can be successfully identified with only minor finite-size effects. Our results establish that, while Delta-VQE provides a resource-efficient probe of quantum criticality without requiring precise ground-state preparation, its diagnostic power is fundamentally contingent upon the judicious selection of physically representative ansätze.
Comments9 pages, 6 figures
