# Universal Mott quantum criticality in a modified periodic Anderson model

## TL;DR

This paper demonstrates that the modified periodic Anderson model exhibits genuine zero-temperature Mott quantum critical points with universal scaling behavior, supported by dynamical mean-field theory and numerical renormalization group analysis.

## Contribution

It shows that the MPAM hosts a surface of continuous Mott quantum critical points with universal critical exponents, unlike the single-band Hubbard model.

## Key findings

- Quantum critical scaling in resistivity with specific exponents
- Robust ω/T scaling in correlation functions
- Distinct optical conductivity signatures at the QCP

## Abstract

Mott quantum criticality is a central theme in correlated electron physics, observed in systems featuring both continuous zero-temperature transitions and those with finite-temperature critical endpoints. Within dynamical mean-field theory (DMFT), the paradigmatic single-band Hubbard model (SBHM) displays such criticality only above a finite-temperature endpoint. In contrast, the modified periodic Anderson model (MPAM) is a rare example known to host a surface of genuinely continuous Mott quantum critical points (QCPs) at zero temperature. Using DMFT with the numerical renormalization group as an impurity solver, we investigate the finite-temperature, real-frequency properties of the MPAM. Our central finding is the emergence of quantum critical scaling in the electrical resistivity, with critical exponents $z_{\text{met}} = 0.76$ and $z_{\text{ins}} = 0.66$ on the metallic and insulating sides, respectively. These values fall within the range reported for the SBHM, suggesting that both transitions are governed by a common universality class. We further substantiate the presence of local quantum criticality by demonstrating robust $\omega/T$ scaling in single- and two-particle correlation functions. Finally, we identify novel transport signatures in the optical conductivity, where the distinct evolution of two isosbestic points serves as a unique fingerprint of the QCP. These results establish the MPAM as a canonical model for investigating genuine Mott quantum criticality and support the existence of a universal framework for this fundamental phenomenon.