Femtomagnetism and Spin Dynamics (Femtomag Team)

Research Topics

In our team we study the dynamical properties of the electrons and their spins in metals and molecular systems. We are particularly interested in the dynamics of correlated spin phases (ferromagnetism or ferrimagnetism), the dynamics of the collective electronic excitations (plasmons) in metals and the vibrational dynamics associated to the molecular motion. We currently develop four main research activities (for more, click on the above button links) : * Ultrafast Magnetization Dynamics (Femtomagnetism) * Spin Photonics * Surface Plasmon Dynamics in Metallic Nanostructures * Ultrafast Molecular Dynamics (wave packet dynamics in conjugated molecules and molecular magnets).

Instrumentation and techniques

The experimental methods that we are using allow us performing time resolved optical and magneto-optical experiments with a femtosecond temporal resolution in the range of a few tens of femtoseconds up to 1 nanosecond.

Femtosecond laser sources:

Oscillators 80 MHz, 800 nm, 500 mW (20 fs & 100 fs); amplified sources at 5 kHz: (120 fs, 200 μJ/pulse) and (40 fs, 500 μJ/pulse). Second harmonic generation (pump at 400 nm) and spectral continuum generation (probe in the visible 500-800 nm); near infra-red Optical Parametric Amplifier (5 kHz, 100 fs, 1.5 – 3 μm); mid-infrared difference frequency mixing (5 kHz, 300 fs, 5-10 μm).

Measurement techniques:

Time resolved Kerr and Faraday magneto-optics; Femtosecond confocal Kerr microscopy (300 nm & 150 fs spatial and temporal resolutions); Pump-probe femtosecond spectroscopy (differential reflectivity and transmission); time resolved photon echo and four wave mixing; Low temperature spectroscopy and magneto-optics (50 – 300 K).

Team Members :

Research Engineer, Ultrafast Optics and Nanophotonics (DON)Marie.Barthelemy@ipcms.unistra.fr
Phone: +33(0)3 88 10 72 51Office: 2408
Research Engineer, Ultrafast Optics and Nanophotonics (DON)Yohann.Brelet@ipcms.unistra.fr
Phone: +33(0)3 88 10 72 51Office: 2408
Professor, Ultrafast Optics and Nanophotonics (DON)Valerie.Halte@ipcms.unistra.fr
Phone: +33(0)3 88 10 72 13 , +33(0)3 88 10 72 78Office: 2406
See personal page
Research Engineer, Ultrafast Optics and Nanophotonics (DON)Mircea.Vomir@ipcms.unistra.fr
Phone: +33(0)3 88 10 72 16Office: 2409

Recent publications :

M. Barthelemy, A. Maghraoui, G. Versini, M. Vomir, J.-Y. Bigot, Multiscale temporal probing of elemental ultrafast magnetization dynamics in permalloy using High order Harmonics, in: Cerullo, G and Ogilvie, J and Kartner, F and Khalil, M and Li, R (Ed.), XXI INTERNATIONAL CONFERENCE ON ULTRAFAST PHENOMENA 2018 (UP 2018), E D P SCIENCES, 2019. https://doi.org/10.1051/epjconf/201920502013.
J. Panigrahi, E. Terrier, S. Cho, V. Halté, Spins Dynamics across Metal-Insulator Transition in Fe3O4 Films, in: 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), 2019: pp. 1–1. https://doi.org/10.1109/CLEOE-EQEC.2019.8871533.
K. Sartori, G. Cotin, C. Bouillet, V. Halté, S. Bégin-Colin, F. Choueikani, B.P. Pichon, Strong interfacial coupling through exchange interactions in soft/hard core-shell nanoparticles as a function of cationic distribution, Nanoscale. 11 (2019) 12946–12958. https://doi.org/10.1039/c9nr02323b.
T.U. Tumkur, M.A. Hurier, M.D. Pichois, M. Vomir, B. Donnio, J.-L. Gallani, M.V. Rastei, Photoinduced Atomic Force Spectroscopy and Imaging of Two-Dimensional Materials, Physical Review Applied. 11 (2019) 044066. https://doi.org/10.1103/PhysRevApplied.11.044066.

Ultrafast Molecular Dynamics

Spin Photonics Microscopy

Surface Plasmon Dynamics in Metallic Nanostructures

Ultrafast Magnetization Dynamics