8:30 - 9:00THZ-INDUCED CARRIER MULTIPLICATION IN TAAS WEYL SEMIMETAL
S. HOUVER1,2, D. SORANZIO2, S. BIASCO2, C. SHEKHAR3, C. FELSER3, E. ABREU2, M. SAVOINI2, S. JOHNSON2,4
1Université Paris Cité, CNRS, Matériaux et Phénomènes Quantiques, F-75013, Paris, France; 2Institute for Quantum Electronics, Physics Department, ETH Zürich, Zürich, Switzerland; 3Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany; 4Swiss Light Source, Paul Scherrer Institut, Villigen PSI, Switzerland
We present recent results of 2D-THz spectroscopy of a bulk Weyl semimetal TaAs in reflection. We highlight THz-induced carrier multiplication effects and study the field and temperature dependence of the THz-excited number of carriers. These studies are a key step to understand THz-induced competing processes in these intriguing materials.
9:00 - 9:30UNE SOURCE THZ HAUTES PERFORMANCES POUR LA SPECTROSCOPIE ET LES TELECOMMUNICATIONS
L. LECHEVALLIER1, L. DJEVAHIRDJIAN1, M.-A. MARTIN-DRUMEL2, O. PIRALI2, R. KASSI3, G. DUCOURNAU3, S. KASSI1
1LIPhy, Laboratoire Interdisciplinaire de Physique, 38400 Saint-Martin d’Hères; 2ISMO, Institut des Sciences Moléculaires d’Orsay, 91400 Orsay; 3IEMN, Institut d’Electronique, de Microélectronique et de Nanotechnologie, 59652 Villeneuve d’Ascq
Nous présenterons le principe de fonctionnement d'une source THz à photomélange laser hautement accordable et de très haute stabilité puis nous montrerons ses performances pour la spectroscopie de très haute résolution référencée aux standards de fréquences, ainsi que pour les télécommunications très haut débit.
9:30 - 9:45ATOMIC-SCALE MICROSCOPY OF DIFFERENT MATERIALS BY ULTRASHORT THZ-DRIVEN ATOM PROBE TOMOGRAPHY
M. DE TULLIO1, I. BLUM1, E. CADEL1, L. CHEVALIER1, J. HOUARD1, M. ROPITAUX2, M. ANDERSSON3, G. ERIKSSON3, A. VELLA1
1GPM – Université de Rouen Normandie; 2Laboratoire Glyco-MEV – Université de Rouen Normandie; 3Department of Chemistry and Chemical Engineering - Chalmers University of Technology
This research introduces terahertz atom probe tomography (THz-APT) as an innovative approach for atomic-scale imaging and analysis. By using single-cycle THz pulses, a unique control is achieved over field-ion emission from positively biased nanotips, enhancing spatial and chemical resolution in the case of materials with different bandgap.
9:45 - 10:00TERAHERTZ AND SECOND-HARMONIC GENERATION IN REFLECTION AT THE SURFACE OF A DIELECTRIC CRYSTAL USING A DOUBLE PULSE LASER EXCITATION
M. KRISTENSEN1, E. HERAULT2, E. SKOVSEN1, J.-L. COUTAZ2,1
1Department of Materials and Production, Section for Physics and Mechanics, Aalborg University, Aalborg East, DK-9220, Denmark; 2Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Grenoble INP, CROMA, Grenoble, 38000, France
We present an original THz generation/detection configuration using an autocorrelation technique. By second-order nonlinear effects, THz and SH signals are generated in reflection at the surface of a dielectric crystal and detected simultaneously. This technic, by detecting weak and broadband THz signals, could be useful for surface spectroscopy.
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