Theory of universal Planckian metal in t-J model: application for high-Tc cuprate superconductors

TL;DR

This paper develops a theoretical model based on a large-N Kondo lattice to explain the universal Planckian metal phase observed in high-Tc cuprates, linking quantum criticality to strange metal behavior.

Contribution

It introduces an analytically solvable model connecting charge Kondo fluctuations to the Planckian metal phase in cuprates, providing a new theoretical framework.

Findings

Model reproduces linear-in-temperature resistivity.

Explains universal scattering rate in strange metals.

Aligns with experimental observations in cuprates.

Abstract

The mysterious quantum-critical Planckian bad metal phase with perfect T-linear resistivity persisting beyond the quasi-particle limit and universal T-linear scattering rate has been observed in various high-Tc cuprate superconductors. Here, we develop a realistic theoretical approach to this phase in an analytically solvable large-N multi-channel Kondo lattice model, derived from a heavy-fermion formulated conventionaL t-J model, known for qualitatively describing cuprates. This phase is originated from critical charge Kondo fluctuations where disordered local bosonic charge fluctuations couple to spinon and heavy conduction-electron Fermi surfaces near a charge-Kondo-breakdown local quantum critical point associated with pseudogap-to-Fermi liquid transition. Our results show excellent agreement with experiments and offer broad implications for other unconventional superconductors.