Charge currents may be generated by pure spin injection via the spin galvanic effect, also referred to as “inverse Rashba – Edelstein effect”, and/or the inverse spin Hall effect. In a typical spin pumping setup consisting of a injector, e.g. a driven magnetic electrode, and a converter, a metallic spin-orbit coupled system, both effects contribute to the conversion. If however the converter is 2D only the spin galvanic channel is available. This is notably the relevant scenario for 2D dimensional electron gases at oxide interfaces. Recent experiments at such interfaces show strongly anisotropic spin- (and orbit-) to charge conversion [1], which I will explain in terms of the “tunneling anisotropic spin galvanic effect” [2]. I will also show how intrinsic time scales heavily affect such conversion in the ultrafast regime [3].
References [1] El Hamdi et al., Nat. Phys. 19, 1855 (2023) [2] Fleury et al., Phys. Rev. B 108, L081402 (2023) [3] El Hamdi et al., Phys. Rev. B 110, 054412 (2024)
Orateur : Rupert Huber (Department of Physics and Regensburg Center for Ultrafast Nanoscopy (RUN) University of Regensburg)
Résumé : The carrier wave of light can drive electrons through solids on time scales faster than a cycle of light. This ‘lightwave electronics’ concept opens a fascinating coherent quantum world full of promise for future quantum technologies. We will discuss prominent examples of lightwave-driven dynamics in solid-state quantum materials, ranging from Bloch oscillations via topologically non-trivial electron trajectories to optical band-structure engineering and attoclocking of Bloch electrons. We also take slow-motion movies of single molecules and atomic defects and observe the quantum flow of electrons with the first all-optical subcycle microscope reaching atomic resolution. Our results offer a radically new way of watching and controlling elementary dynamics in nature or steer chemical reactions, on their intrinsic spatio-temporal scales.
Aram Yoon (Shell Energy Transition Center, Amsterdam)
Résumé : Electrocatalysis plays a pivotal role in various energy conversion and storage applications, including fuel cells, electrolyzers, and batteries. It facilitates the conversion of chemicals from one form to another, making it essential for clean and sustainable energy technologies. Transition metal oxides show great promise in this regard, as they are abundant on Earth and can modify their electrical and chemical properties by adjusting their oxidation state through surface and interface engineering. To effectively harness these materials in energy conversion devices, it is imperative to gain insights into how catalysts’ structures behave in working environments, as this significantly influences chemical conversions and the catalysts’ own chemical status. However, investigating the structure and chemistry of electrocatalysts under electrochemical reaction conditions is a challenging endeavor. Electrochemical systems involve reactions and transformations occurring at multiphase boundaries, including solid-solid and solid-liquid interfaces. This complexity necessitates the use of diverse techniques to probe these interfaces, further complicated by the need to maintain the electrolyte and applied potential.
In my presentation, I will delve into the behavior of Cu2O catalysts under dynamic reaction conditions, employing a multimodal approach centered on in situ Electrochemical Cell Transmission Electron Microscopy (EC-TEM). This approach will focus on two conversion reactions involving Cu2O catalysts: electrochemical CO2 reduction and nitrate reduction. Through this investigation, I will demonstrate structural changes of Cu2O catalysts during redox reactions. The primary emphasis will be on correlating various operando techniques, such as X-ray absorption microscopy and spectroscopy, with electrochemical characterization to gain a comprehensive understanding of how structural heterogeneity impacts catalysis.
Pour tout contact : Maria Letizia De Marco (0388107028 – maria-letizia.demarco@ipcms.unistra.fr)
Abhishake MONDAL (Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore)
Abstract :
The pursuit of smart multifunctional materials with stimuli-responsive magnetic and optical response has drawn escalating interest in both fundamental science and potential applications to switches, sensors, and intelligent devices.1 One of the appealing feature of such materials is the tunability of their physical property via chemistry, where the linking structure and physical properties can be modulated in practically infinite ways, which gives them an edge over the solid-state magnetic materials (Figure 1, a).2 The field of molecular bistable systems is rapidly budding towards utilizing these molecule-based magnetic materials in physics-driven and nanotechnology-driven fields (Figure 1, b).
Figure 1: a) Stimuli-responsive molecular bistable systems and b) Application areas where these systems are actively studied for developing devices
Here, I will briefly cover the exciting field of Molecular Magnetism and will specifically focus on three most important aspects of Molecular Magnetism being pursued in my laboratory i) Spin Crossover (SCO) materials3 ii) Metal-to-Metal Electron Transfer Systems (MMET)4 and iii) Single Molecule Magnets (SMM).5 Lastly, I shall discuss the application of these bistable systems in developing ring-resonator devices for Photonics Application, molecular break junctions and microelectromechanical systems.
Acknowledgments: I thank the Indian Institute of Science (IISc), Bangalore, India, and the Ministry of Human Resource Development (MHRD), Ministry of Education (MoE), Government of India, IISc-Start-up Research Grant, the Department of Science and Technology, Mission on Nano Science and Technology (Nano Mission), Scheme for Transformational and Advanced Research in Sciences (STARS, MHRD), Council of Scientific and Industrial Research (CSIR) for the research fundings.
Paul ROBINEAU (Institut pluridisciplinaire Hubert Curien)
Pour votre information, Paul Robineau sera candidat auprès de la commission interdisciplinaire (CID) 52 du CNRS intitulée « Environnements sociétés: du savoir à l’action ».
