Theoretical Reproduction of the Lineshapes of Nonlinear Conductance Observed in a Quantum Point Contact

TL;DR

This paper presents a theoretical model that reproduces the nonlinear conductance lineshapes in quantum point contacts across various bias voltages, explaining features like side peaks and zero-bias anomalies.

Contribution

It introduces a theoretical approach using the Anderson model with asymmetric Kondo couplings to explain experimental conductance features in quantum point contacts.

Findings

Reproduces conductance lineshapes across bias range

Identifies origin of side peaks in conductance

Analyzes zero-bias anomaly behavior

Abstract

The nonlinear conductance observed in a quantum point contact is theoretically reproduced for the entire range of applied bias. The single-impurity Anderson model with two reservoirs at different chemical potentials is studied for a sequential change of the gate voltage. The imbalance in the left and right Kondo coupling strength is introduced by the displacement of the Kondo impurity by the electric field produced in the constriction of quantum point contact. We reveal the origin of the side peaks and study the behavior of the height and width of the zero-bias anomaly.