Unified explanation of the Kadowaki-Woods ratio in strongly correlated materials

TL;DR

This paper introduces a unified ratio related to the Kadowaki-Woods ratio that accounts for carrier density and dimensionality, revealing a common underlying physics across diverse strongly correlated materials.

Contribution

It proposes a new ratio that explains the consistent values of the Kadowaki-Woods ratio across various materials by including density and dimensional effects.

Findings

The new ratio predicts the same value in different classes of materials.

It explains the variation in the original Kadowaki-Woods ratio.

No exotic physics are needed to understand the ratio's universality.

Abstract

Discoveries of ratios whose values are constant within broad classes of materials have led to many deep physical insights. The Kadowaki-Woods ratio (KWR) compares the temperature dependence of a metal's resistivity to that of its heat capacity; thereby probing the relationship between the electron-electron scattering rate and the renormalisation of the electron mass. However, the KWR takes very different values in different materials. Here we introduce a ratio, closely related to the KWR, that includes the effects of carrier density and spatial dimensionality and takes the same (predicted) value in organic charge transfer salts, transition metal oxides, heavy fermions and transition metals - despite the numerator and denominator varying by ten orders of magnitude. Hence, in these materials, the same emergent physics is responsible for the mass enhancement and the quadratic temperature dependence of the resistivity and no exotic explanations of their KWRs are required.