Institut des
NanoSciences de Paris
insp
Accueil > Evénements > Séminaires > Shot-noise scanning (...)
insp
2.jpg

Shot-noise scanning tunnelling microscopy : noisy defects in a doped Mott insulator - Freek Massee - Mardi 6 novembre 2018 à 11 h

INSP - Sorbonne Université - 4 place Jussieu - 75005 Paris - Barre 22-32, 2e étage, salle 201

Freek Massee - Chargé de recherche au Laboratoire de Physique des solides (CNRS et Université Paris-Saclay)

Abstract

A direct consequence of the discreteness of the electron charge is the presence of time-dependent fluctuations of the electronic current, called shot-noise. Since shot-noise is directly sensitive to the charge of the current carrying entities, as well as to their dynamics, shot-noise has been a powerful tool in the study of mesoscopic systems [1]. In this talk I will present how we managed to increase the spatial resolution of shot-noise measurements to the atomic level by implementing cryogenic circuitry operating in the MHz regime into our home-built scanning tunnelling microscope [2]. After discussing the details of the circuitry, I will demonstrate its application to the high temperature superconductor Bi2Sr2CaCu2O8+x, where we find atomically sized objects with a strongly enhanced current noise [3]. I will discuss the origin of these remarkable objects, and possibilities to use them to study superconductivity.

[1] Ya. M. Blanter and M. Büttiker, Physics Report 336, 1 (2000)
[2] F. Massee et al., Rev. Sci. Instrum. 89, 093708 (2018)
[3] F. Massee et al., arXiv:1809.09840 (2018)