Universal relations between thermoelectrics and noise in mesoscopic transport across a tunnel junction

TL;DR

This paper presents a unified theory revealing universal relations between thermoelectric and noise properties in mesoscopic transport, applicable across various quantum systems, and highlights how violations signal new energy scales.

Contribution

It introduces a comprehensive framework linking thermoelectric and noise observables in mesoscopic systems, demonstrating universality across multiple quantum models.

Findings

Universal relations between charge, heat, and noise in quantum transport.

Application to diverse quantum systems showing consistent universal behavior.

Violations of relations indicate emergence of new energy scales.

Abstract

We develop a unified theory of weakly probed differential observables for currents and noise in transport experiments. Our findings uncover a set of universal transport relations between thermoelectric and noise properties of a system probed through a tunnel contact, with the Wiedemann-Franz law being just one example of such universality between charge and heat currents. We apply this theory to various quantum systems, including multichannel Kondo, quantum Hall and Sachdev-Ye-Kitaev quantum dots, resonant impurity, and two-stage Kondo models and demonstrate that each of the microscopic theories is characterized by a set of universal relations connecting conductance and thermoelectrics with noise. Violations of these relations indicate additional energy scales emerging in a system.