Incipient singlet-triplet states in a hybrid mesoscopic system

TL;DR

This paper presents a method to observe the singlet-triplet Kondo effect in a hybrid mesoscopic system involving a quantum point contact and an electronic cavity, revealing conductance-dependent anomalies.

Contribution

It introduces an accessible approach to induce and study the singlet-triplet Kondo effect in a hybrid quantum system with conductance-dependent phenomena.

Findings

Zero-bias anomaly at low conductance

Coexistence of zero-bias and finite-bias anomalies at medium conductance

Finite-bias anomaly only at high conductance

Abstract

In the present work we provide an easily accessible way to achieve the singlet-triplet Kondo effect in a hybrid system consisting of a quantum point contact (QPC) coupled to an electronic cavity. We show that by activating the coupling between the QPC and cavity, a zero-bias anomaly occurs in a low conductance regime, a coexistence of zero-bias and finite-bias anomaly (FBA) in a medium conductance regime, and a FBA-only anomaly in a high conductance regime. The latter two observations are due to the singlet-triplet Kondo effect.