Séminaire DCMI – Axes 4 et 5 présenté par Paul STEADMAN

Speaker: Paul STEADMAN (Responsable de la ligne I10 au Synchroton Diamond)

Abstract : A study of the electric current induced hysteresis in Pt/CoFeTaB thin films revealed an unexpected behaviour in the hysteresis curves measured using polarised soft X-ray reflectivity [1]. Following a detailed study of the polarisation dependence of the reflected intensity [2] both detailed calculations and experimental data revealed that the switching is Y type (magnetisation switching perpendicular to the current), is very sensitive to external magnetic fields and that, rather bizarrely, only part of the film is switching. In addition the importance of non-linear dependence on the magnetic scattering and its dependence on polarisation and energy have been uncovered experimentally and explained with a very simple model.

  • [1] D. M. Burn, R. Fan, O. Inyang, M. Tokac¸ L. Bouchenoire, A. T. Hindmarch and P. Steadman, P. (2022). Phys. Rev. B, 106, 094429.
  • [2] Raymond Fan, Kiranjot, Razan O. M. Aboljadayel, Kalel Alsaeed, Peter, J. Synchrotron Rad. (2024). 31, 493–507

Séminaire Axe 1 et DON, présenté par Saad Yalouz

Orateur : Saad Yalouz (Laboratoire de Chimie Quantique de Strasbourg)

Résumé : In the realm of quantum computing, the characterization of many-body systems stands out as one of the most promising applications for emerging quantum platforms. While significant effort has been dedicated to developing near-term quantum algorithms for describing purely fermionic systems (particularly for Quantum Chemistry), there exists a gap in extending beyond the “bare” electronic structure to encompass the influence of an external environment. This gap becomes apparent when considering hybrid “fermion+boson” systems, which naturally arise when the electronic structure of a system interacts with an external bosonic field, such as photons or phonons. The theoretical description of such systems poses a considerable challenge, necessitating the depiction of entanglement between the two types of particles. Addressing this challenge defines an interesting target for quantum computers. In this presentation, I will delve into recent endeavors initiated at the Laboratoire de Chimie Quantique Strasbourg to tackle these questions. Drawing from a polaritonic chemistry problem, I will elucidate how we are currently designing near-term quantum algorithms to describe both ground and excited states in such systems

Contact : Paul-Antoine Hervieux  

Séminaire Axe 3 présenté par Dr. Maurizio Mastropasqua Talamo

Dr. Maurizio Mastropasqua Talamo (Laboratoire Moltech-Anjou, Université d’Angers)

Résumé :

Starting from initial purposes of molecular recognition, the study of chiral pi-conjugated molecules and supramolecular assemblies have led over time to a deeper understanding of chirality-related properties which do not only rely upon geometric pairing but also involve polarization in light-matter interaction and spin selectivity in charge transport. These new properties have boosted the interest in the development of chiral organic semiconductors for advanced optoelectronics applications.

Many asymmetric synthetic techniques which are particularly important in the field of pharmaceutical synthesis, can enable the practical modification of pi-conjugated scaffolds with various stereogenic motifs, resulting in molecular semiconductors and chromophores showcasing diverse chirality-related properties.

Some examples of asymmetric modification of molecular semiconductors and chromophores will be given in this lecture along with a discussion about chirality-related properties observed within the newly synthesized materials.