Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX 77005.
Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
Proc Natl Acad Sci U S A. 2023 Jul 25;120(30):e2300903120. doi: 10.1073/pnas.2300903120. Epub 2023 Jul 17.
Strange metals appear in a wide range of correlated materials. Electronic localization-delocalization and the expected loss of quasiparticles characterize beyond-Landau metallic quantum critical points and the associated strange metals. Typical settings involve local spins. Systems that contain entwined degrees of freedom offer new platforms to realize unusual forms of quantum criticality. Here, we study the fate of an SU(4) spin-orbital Kondo state in a multipolar Bose-Fermi Kondo model, which provides an effective description of a multipolar Kondo lattice, using a renormalization-group method. We show that at zero temperature, a generic trajectory in the model's parameter space contains two quantum critical points, which are associated with the destruction of Kondo entanglement in the orbital and spin channels, respectively. Our asymptotically exact results reveal an overall phase diagram, provide the theoretical basis to understand puzzling recent experiments of a multipolar heavy fermion metal, and point to a means of designing different forms of quantum criticality and strange metallicity in a variety of strongly correlated systems.
奇异金属出现在广泛的关联材料中。电子局域-离域和预期的准粒子损失是超越朗道金属量子临界点和相关奇异金属的特征。典型的设置涉及局部自旋。包含缠结自由度的系统为实现不同寻常形式的量子临界点提供了新的平台。在这里，我们使用重整化群方法研究了多极玻色-费米 Kondo 模型中 SU(4)自旋轨道 Kondo 态的命运，该模型为多极 Kondo 格子提供了有效的描述。我们表明，在零温度下，模型参数空间中的一条一般轨迹包含两个量子临界点，它们分别与轨道和自旋通道中 Kondo 纠缠的破坏有关。我们的渐近精确结果揭示了一个整体相图，为理解最近多极重费米金属的实验提供了理论基础，并指出了在各种强关联系统中设计不同形式的量子临界点和奇异金属的方法。
