# Thermoelectric Transport through SU(N) Kondo Impurity

## TL;DR

This paper studies thermoelectric transport through SU(N) Kondo impurities, revealing non-linear effects and potential for thermopower enhancement, with implications for quantum dot and nanotube experiments.

## Contribution

It provides a detailed theoretical analysis of thermoelectric effects in SU(N) Kondo systems using the local Fermi-liquid paradigm and Keldysh technique, including non-linear phenomena.

## Key findings

- Pronounced non-linear effects in low-temperature thermopower.
- Enhanced thermopower in specific SU(4) regimes.
- Influence of potential scattering and asymmetry on transport.

## Abstract

We investigate thermoelectric transport through a SU(N) quantum impurity in the Kondo regime. The strong coupling fixed point theory is described by the local Fermi-liquid paradigm. Using Keldysh technique we analyse the electric current through the quantum impurity at both finite bias voltage and finite temperature drop across it. The theory of a steady state at zero-current provides a complete description of the Seebeck effect. We find pronounced non-linear effects in temperature drop at low temperatures. We illustrate the significance of the non-linearities for enhancement of thermopower by two examples of SU(4) symmetric regimes characterized by a filling factor m: i) particle-hole symmetric at m=2 and ii) particle-hole non-symmetric at m=1. We analyse the effects of potential scattering and coupling asymmetry on the transport coefficients. We discuss connections between the theory and transport experiments with coupled quantum dots and carbon nanotubes.