Transmission phase evolution in fully screened and overscreened Kondo impurities

TL;DR

This paper investigates the transmission phase evolution in fully screened and overscreened Kondo impurities using advanced theoretical frameworks, revealing measurable Fermi-liquid coefficients and temperature effects relevant for experimental validation.

Contribution

It provides a detailed analysis of the transmission phase and visibility in SU(N) Kondo systems, highlighting temperature corrections and proposing experimental tests for non-Fermi-liquid regimes.

Findings

Fermi-liquid coefficients for fully screened Kondo effects identified

Temperature correction effects in non-Fermi-liquid regimes analyzed

Proposals for experimental verification in quantum dot structures

Abstract

We study the coherent properties of fully screened and overscreened Kondo effects based on the Nozieres local Fermi-liquid theory and Affleck-Ludwig boundary conformal-field-theory approach, respectively. Coherent transports through an SU($N)$ generalization of fully screened and the multi-$\mathcal{K}$-channel overscreened Kondo impurities at and beyond the particle-hole (PH) symmetric point are thoroughly investigated. We report distinctive Fermi-liquid coefficients characterizing the finite temperature correction to the transmission phase shift and normalized visibility in fully screened Kondo regime, which can be measured with the existing experimental setups. Our work equally uncovers the significance of temperature correction to the transmission phase shift and visibility in non Fermi-liquid regime associated with the PH asymmetric overscreened Kondo effects with an arbitrary number of conduction channels $\mathcal{K}$. We propose viable roots of verifying our predictions in connection to the recent experiments, in particular with the experiments studying highly symmetric forms of fully screened Kondo effects and two-channel overscreened Kondo effects realized in quantum dot nano-structures.