Delta-T noise in the Kondo regime

TL;DR

This paper investigates delta-T noise in the SU(2) Kondo quantum dot, proposing a measurable quantity to analyze low-temperature charge current noise under temperature bias, and compares behaviors under different bias conditions.

Contribution

It introduces a new measurable quantity for delta-T noise in the Kondo regime and analyzes its behavior, highlighting differences due to Fermi distribution functions.

Findings

$S_{ ext{ell}}$ behaves similarly under electrochemical potential and temperature bias.

Quantitative differences in noise coefficients reflect Fermi distribution variations.

The proposed quantity reduces to shot noise in the noninteracting limit.

Abstract

We study the delta-T noise in the Kondo regime, which implies the charge current noise under the temperature bias for the SU(2) Kondo quantum dot. We propose an experimentally measurable quantity to quantify the low-temperature properties in the delta-T noise: $S_{\ell}=S(T_{\mathrm{L}},T_{\mathrm{R}}) - (1/2)[S(T_{\mathrm{L}},T_{\mathrm{L}}) + S(T_{\mathrm{R}},T_{\mathrm{R}})]$, which yields the shot noise expression in the noninteracting limit. We calculate this quantity for the SU(2) Kondo quantum dot in the particle-hole symmetric case. We found that the $S_{\ell}$ exhibits qualitatively the same behavior in both the electrochemical potential biased case and the temperature biased case. The quantitative difference appears as a difference of the coefficients of the noises, which reflects the difference of the Fermi distribution function: electrochemical potential biased or temperature biased.