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

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.