近日，南方科技大学张文清团队研究了团簇自旋玻璃中出现的量子临界相。这一研究成果于2025年11月6日发表在《国家科学评论》杂志上。

强关联电子研究显著拓展了凝聚态物理的前沿疆域，尤其在关联驱动量子相变领域。在量子相变临界区域，多自由度量子临界涨落催生了超越朗道范式的奇异多体态与量子临界行为。近年来，传统上被认为与绝缘磁体相关的磁阻挫效应，已被视为研究对称性破缺无关的关联驱动近藤破坏量子相变中新物相的关键因素。然而这些新物相的本质仍待深入探索。

研究组报道了在重费米子金属TiFe_xCu_2x-1Sb中由团簇自旋玻璃态涌现的量子临界现象，其阻挫源于体系固有的无序性。变磁场下的比热与磁Grüneisen参数测量显示出量子临界标度行为，指示体系在0.13特斯拉附近存在量子临界点。随着磁场增强，团簇自旋玻璃相被逐渐抑制。在穿越量子临界点时，电阻率与霍尔效应测量揭示了局域矩增强的屏蔽效应与扩张的费米面，这与近藤破坏理论图像相符。该发现揭示了一类新型铁基重费米子金属家族，其中多自由度的复杂交织为探索非常规激发与奇异量子临界态提供了新平台。

附：英文原文

Title: Emerging quantum critical phase in a cluster spin-glass

Author: Zhang, Fang, Feng, Tao, Ruan, Yurong, Ye, Xiaoyuan, Wen, Bing, Zhou, Liang, He, Minglin, Zhuang, Zhaotong, Wu, Liusuo, He, Hongtao, Sun, Peijie, Yu, Zhiyang, Liu, Weishu, Zhang, Wenqing

Issue&Volume: 2025-11-06

Abstract: The study of strong electron correlations has significantly advanced the frontiers of condensed matter physics, especially in relation to correlation-driven quantum phase transitions (QPTs). In the vicinity of QPTs, quantum critical fluctuations of multiple degrees of freedom enable the emergence of exotic many-body states and quantum critical behaviours beyond the Landau paradigm. Recently, magnetic frustration, traditionally associated with insulating magnets, has been recognized as pivotal to investigating new phases of matter in correlation-driven Kondo breakdown QPTs that are not clearly associated with broken symmetry. The nature of these new phases, however, remains underexplored. Here, we report quantum criticalities emerging from a cluster spin-glass in the heavy-fermion metal TiFexCu2x-1Sb, where frustration originates from intrinsic disorder. Specific heat and magnetic Grüneisen parameter measurements under varying magnetic fields exhibit quantum critical scaling, indicating a quantum critical point (QCP) near 0.13 Tesla. As the magnetic field increases, the cluster spin-glass phase is progressively suppressed. Upon crossing the QCP, resistivity and Hall effect measurements reveal enhanced screening of local moments and an expanding Fermi surface, consistent with the Kondo breakdown scenario. Our findings uncover a new family of iron-based heavy-fermion metals with intricate interplay of multiple degrees of freedom, enabling the exploration of unconventional excitations and exotic quantum critical states and behaviours.

DOI: 10.1093/nsr/nwaf483

Source: https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaf483/8316140searchresult=1