École Thématique « Molecular Photochemistry »

L’école est organisée sur trois jours intensifs et comprendra des cours frontaux (environ 18 heures) ainsi que des exercices et des sessions de Questions & Réponses (environ 3 heures) dispensés par des intervenants locaux, nationaux et internationaux. Les cours seront présentés en anglais.

Liste des intervenants :

  • Pr. Vincent Robert (LCQ, Université de Strasbourg & CNRS)
  • Pr. Stefan Haacke (IPCMS-DON, Université de Strasbourg & CNRS)
  • Dr. Chantal Daniel (LCQ, Université de Strasbourg & CNRS)
  • Pr. Lorenzo Di Bari (Dept. of Chemistry, University of Pisa, Italie)
  • Pr. Ally Aukauloo (ICMMO, Université Paris-Saclay)
  • Dr. Pascal Didier (Faculté de Pharmacie, Université de Strasbourg & CNRS)
  • Pr. Federico Polo (DMSN, Ca’ Foscari University of Venice, Italie)
  • Dr. Giulio Ragazzon (ISIS, Université de Strasbourg & CNRS)
  • Dr. Alberto Barsella (IPCMS-DON, Université de Strasbourg & CNRS)
  • Dr. Loïc Mager (IPCMS-DON, Université de Strasbourg & CNRS)
  • Dr. Jérémie Léonard (IPCMS-DON, Université de Strasbourg & CNRS)
  • Dr. Matteo Mauro (IPCMS-DMO, Université de Strasbourg & CNRS)

Voir le PROGRAMME

Séminaire IPCMS présenté par Gwendal FEVE

Gwendal FEVE

Professeur à Sorbonne Université
Laboratoire de Physique de l’ENS

Abstract:

In three-dimensional space, elementary particles are divided between fermions and bosons according to the properties of symmetry of the wave function describing the state of the system when two particles are exchanged. When exchanging two fermions, the wave function acquires a phase, φ=π . On the other hand, in the case of bosons, this phase is zero, φ=0. This difference leads to deeply distinct collective behaviors between fermions, which tend to exclude themselves, and bosons which tend to bunch together. The situation is different in two-dimensional systems which can host exotic quasiparticles, called anyons, which obey intermediate quantum statistics characterized by a phase φ varying between 0 and π [1,2].

            For example in the fractional quantum Hall regime, obtained by applying a strong magnetic field perpendicular to a two-dimensional electron gas, elementary excitations carry a fractional charge [3,4] and have been predicted to obey fractional statistics [1,2] with an exchange phase φ=π/m (where m is an odd integer). I will present how fractional statistics of anyons can be demonstrated in this system by implementing and studying anyon collisions at a beam-splitter [5,6]. The collisions are first studied in the low magnetic field regime, where the elementary excitations are electrons which obey the usual fermionic statistics. It leads to the observation of an antibunching effect in an electron collision: electrons systematically exit in two different arms of the beam-splitter. The observed result is completely different in the fractional quantum Hall regime. Fractional statistics leads to a suppression of the antibunching effect and quasiparticles tend to bunch together in larger packets of charge in a single output of the splitter. This effect leads to the observation of negative correlations of the current fluctuations [6] in agreement with recent theoretical predictions [5].

References :

[1] B. I. Halperin, Phys. Rev. Lett. 52, 1583–1586 (1984).

[2] D. Arovas, J. R. Schrieffer, F. Wilczek, Phys. Rev. Lett. 53, 722–723 (1984).

[3] R. de Picciotto et al., Nature 389, 162–164 (1997).

[4] L. Saminadayar, D. C. Glattli, Y. Jin, B. Etienne, Phys. Rev. Lett. 79, 2526–2529 (1997)

[5] B. Rosenow, I. P. Levkivskyi, B. I. Halperin, Phys. Rev. Lett. 116, 156802 (2016).

[6] H. Bartolomei et al. Science 368, 173-177 (2020).

QMat Mini-Symposium

14:00 Yael ROICHMAN, Department of Physical Chemistry, Tel Aviv University –
Title to be announced


14:45 Antonio STOCCO, Institut Charles Sadron, Strasbourg – Dynamics of a
hard colloid interacting with a soft membrane


15:30 Coffee break


15:45 Vincent HARDEL, Institut de Physique et Chimie des Matériaux de
Strasbourg – Quantum mechanics as Brownian motion