The scaled-invariant Planckian metal and quantum criticality in Ce1−xNdxCoIn5

• Published in: Nature communications 2023-02, Vol.14 (1), p.581-581, Article 581
• Main Authors: Chang, Yung-Yeh, Lei, Hechang, Petrovic, C., Chung, Chung-Hou
• Format: Article
• Language: English
• Subjects: 639/766/119/1003; 639/766/119/2795; Antiferromagnetism; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Critical point; Electrical resistivity; Fermions; Heavy fermion superconductors; Humanities and Social Sciences; Hybridization; Magnetic fields; Metals; multidisciplinary; Phase transitions and critical phenomena; Scattering; Science; Science (multidisciplinary); Superconducting properties and materials
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-36194-9

The mysterious Planckian metal state, showing perfect T -linear resistivity associated with universal scattering rate, 1/ τ  =  α k B T /ℏ with α  ~ 1, has been observed in the normal state of various strongly correlated superconductors close to a quantum critical point. However, its microscopic origin and link to quantum criticality remains an outstanding open problem. Here, we observe quantum-critical T / B -scaling of the Planckian metal state in resistivity and heat capacity of heavy-electron superconductor Ce 1− x Nd x CoIn 5 in magnetic fields near the edge of antiferromagnetism at the critical doping x c  ~ 0.03. We present clear experimental evidences of Kondo hybridization being quantum critical at x c . We provide a generic microscopic mechanism to qualitatively account for this quantum critical Planckian state within the quasi-two dimensional Kondo-Heisenberg lattice model near Kondo breakdown transition. We find α is a non-universal constant and depends inversely on the square of Kondo hybridization strength. The Planckian metal is a special case of a strange metal, in which the linear-in-temperature scattering rate reaches a universal limit. Here the authors study this state in a heavy-fermion superconductor in magnetic field and propose a microscopic mechanical based on quantum criticality of the Kondo hybridization.