Principal Investigator :

Benoit Chalopin ()
LCAR (Femto)

Type of project : Disruptive Project

Date (start/end) : 2018 - 2020

     

Measurement of single electron arrival times for metallic and non-metallic nanotips.

      

Abstract

This project aims at measuring temporal statistics of free electrons emitted from nanometer-size field emitter (field emission nanotips). This type of measurement is well known in photonic quantum optics and electron quantum optics in circuits but has not been used yet for free electrons in the counting regime. We will provide a way to characterize the quantum noise associated to field emission. This is a necessary step towards more complex free space electron quantum optics experiments.

Temporal statistics of emitted electrons are naturally dependent on both the conduction mechanisms inside the nanotip and the emission process. In the case of a metallic nanotip, where ohmic conduction is associated to cold field emission at the apex, the shot-noise correspond to a poissonian distribution of emitted electrons. However, for intense applied electric fields or in the case of non-metallic materials with low conductance, the statistics can be modified so that sub-poissonian statistics could be observed. This type of measurement could give insights into the conduction and emission mechanisms in the case of non-metallic emitters such as diamond.

A dedicated detection setup with a combination of high quantum efficiency single electron detector and high temporal resolution time-to-digital converter will be developed. Free electrons arrival times will be measured for metallic nanoemitters the expected poissonian fluctuations will be tested in the high current case. Emission from non-metallic nanotips will also be investigated, starting with diamond.