Scanning Gate Microscopy of Kondo Dots: Fabry-P\'erot Interferences and Thermally Induced Rings

TL;DR

This paper investigates how scanning gate microscopy can reveal interference patterns and thermally induced rings in a quantum dot system, enabling measurement of magnetic moments via electron interferometry.

Contribution

It demonstrates how thermally induced rings in conductance maps can be used to measure the magnetic moment of a Kondo quantum dot.

Findings

Thermally induced rings are observable alongside Fabry-Pérot fringes.

Ring positions correlate with the magnetic moment of the quantum dot.

Method allows magnetic moment measurement above the Kondo temperature.

Abstract

We study the conductance of an electron interferometer formed in a two dimensional electron gas between a nanostructured quantum contact and the charged tip of a scanning gate microscope. Measuring the conductance as a function of the tip position, thermally induced rings may be observed in addition to Fabry-P\'erot interference fringes spaced by half the Fermi wavelength. If the contact is made of a quantum dot opened in the middle of a Kondo valley, we show how the location of the rings allows to measure by electron interferometry the magnetic moment of the dot above the Kondo temperature.