Publications de Majed Chergui | EPFL Graph Search

All Hard X-ray Transient Grating Spectroscopy

Optical-domain transient grating (TG) spectroscopy is the ideal tool to investigate transport phenomena in gases, liquids and solids, but it is limited to typically micron-size grating periods. Extreme-Ultraviolet TG has represented a major leap forward to ...

NATURE PORTFOLIO2025

Linear and Nonlinear X-ray Spectra of Chiral Molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of Fenchone and Cysteine

Majed Chergui

American Chemical Society (ACS)2025

Ultraviolet Superradiance from Mega-Networks of Tryptophan in Biological Architectures

Majed Chergui, Katrin Elisabeth Oberhofer

Networks of tryptophan (Trp)& horbar;an aromatic amino acid with strong fluorescence response & horbar;are ubiquitous in biological systems, forming diverse architectures in transmembrane proteins, cytoskeletal filaments, subneuronal elements, photorecepto ...

Amer Chemical Soc2024

Light-induced renormalization of the band structure of chiral tellurium

Majed Chergui, Marco Grioni, Michele Puppin, Ji Dai, Serhii Polishchuk

Chirality in tellurium arises from a Peierls distortion driven by strong electron-phonon coupling, making this material a unique candidate for observing a light-induced topological phase transition. Using time- and angle-resolved photoelectron spectroscopy ...

2024

A setup for hard x-ray time-resolved resonant inelastic x-ray scattering at SwissFEL

Majed Chergui, Michele Puppin, Giulia Fulvia Mancini, Ludmila Maria Diniz Leroy, Hui-Yuan Chen, Rolf Baldwin Versteeg

We present a new setup for resonant inelastic hard x-ray scattering at the Bernina beamline of SwissFEL with energy, momentum, and temporal resolution. The compact R = 0.5 m Johann-type spectrometer can be equipped with up to three crystal analyzers and al ...

Aip Publishing2024

Band Gap Renormalization at Different Symmetry Points in Perovskites

Majed Chergui, Lijie Wang

Using ultrafast broad-band transient absorption (TA) spectroscopy of photoexcited MAPbBr3 thin films with probe continua in the visible and the mid- to deep-ultraviolet (UV) ranges, we capture the ultrafast renormalization at the fundamental gap at the R s ...

Amer Chemical Soc2024

Dynamics of the charge transfer to solvent process in aqueous iodide

Majed Chergui, Alfredo Pasquarello, Jinggang Lan

Charge-transfer-to-solvent states in aqueous halides are ideal systems for studying the electron-transfer dynamics to the solvent involving a complex interplay between electronic excitation and solvent polarization. Despite extensive experimental investiga ...

Nature Portfolio2024

Asymmetric conformation of the high-spin state of iron(II)-tris(2,2-bipyridine): Time-resolved x-ray absorption and ultraviolet circular dichroism

Majed Chergui, Malte Oppermann

We analyze the structures of the low-spin (LS) ground state and the high-spin (HS) lowest excited state of the iron-(II)-tris bipyridine complex ([Fe(bpy)3]2+) using density functional theory PBE methods, modeling the solvent interactions with conductor-li ...

2024

Separation of kinetic rate orders in extreme ultraviolet transient grating spectroscopy

Majed Chergui, Michele Puppin, Giulia Fulvia Mancini, Camila Bacellar Cases Da Silveira, Oliviero Cannelli, Rebecca Ann Ingle, Serhii Polishchuk, Hugo Jean Baptiste Marroux

We present an extreme ultraviolet (EUV) transient grating (TG) experiment of the spinel Co3O4 compound using tuneable incident energies across the Co M-2,M-3-edge and a 395 nm probe pulse, detecting both the first and the second diffraction orders (SDOs). ...

IOP Publishing2024

Non-equilibrium Inter-site Dynamics of Photoexcited Kitaev α-Li2IrO3

Majed Chergui, Fabrizio Carbone, Hui-Yuan Chen, Rolf Baldwin Versteeg

The inter-site transition dynamics in a 2D honeycomb lattice of the Mott-insulator Li2irO3 was investigated via broadband time-resolved spectroscopy. Through two excitation regime corresponding to charger transfer (3.1eV) and across Mott-gap excitation (0. ...

Institute of Electrical and Electronics Engineers Inc.2024