Quantum Criticality by Interaction Frustration in a Square-Planar Lattice
Abstract
We report experimental and theoretical investigations on ThCrGeC, a metallic compound in which CrC planes form a square-planar lattice. Neutron powder diffraction, magnetization, and specific heat measurements reveal no evidence of long-range magnetic order or short-range spin freezing down to 70~mK. Quantum critical behavior was indicated through logarithmic divergences in both the magnetic susceptibility and the specific heat divided by temperature. Resistivity measurements exhibit non-Fermi-liquid behavior, with a Fermi liquid recovered under magnetic fields or high pressures. First-principles calculations identify competing nearest-neighbor () and next-nearest-neighbor () exchange interactions, with , pointing to strong magnetic frustration. The interaction frustration is reduced, and magnetically ordered phases are stabilized upon the application of negative or positive pressures. This work offers a rare example of zero-field, ambient pressure quantum criticality mainly driven by interaction frustration in a square lattice.
Cite
@article{arxiv.2507.22362,
title = {Quantum Criticality by Interaction Frustration in a Square-Planar Lattice},
author = {Yi-Qiang Lin and Chang-Chao Liu and Jia-Xin Li and Bai-Jiang Lv and Kai-Xin Ye and Jia-Wen Zhang and Si-Qi Wu and Ya-Nan Zhang and Ye Chen and Jia-Yi Lu and Jing Li and Hua-Xun Li and Hao Li and Yi Liu and Cao Wang and Yun-Lei Sun and Hao Jiang and Hui-Qiu Yuan and Guang-Han Cao},
journal= {arXiv preprint arXiv:2507.22362},
year = {2025}
}
Comments
17 pages, 13 figures, and 6 tables