217 citations · 1k across the 11 of their papers we have counts for
11 papers
Landau Theory for Non-Symmetry-Breaking Electronic Instability Coupled to Symmetry-Breaking Applied to Prussian Blue Analogue
Giovanni Azzolina, Roman Bertoni, Claude Ecolivet +3
Different types of ordering phenomena may occur during phase transitions, described within the universal framework of the Landau theory through the evolution of one, or several, sy…
Strain Wave Pathway to Semiconductor-to-Metal Transition revealed by time resolved X-ray powder diffraction
C. Mariette, M. Lorenc, H. Cailleau +42
Thanks to the remarkable developments of ultrafast science, one of today's challenges is to modify material state by controlling with a light pulse the coherent motions that connec…
Lattice phonon modes of the spin crossover crystal [Fe(phen)2(NCS)2] studied by THz, IR, Raman spectroscopies and DFT calculations
Eric Collet, Giovanni Azzolina, Tomoaki Ichii +9
[Fe(phen)2(NCS)2] is a prototype transition metal complex material, which undergoes a phase transition between low-spin (LS) and high-spin (HS) phases, induced by temperature, pres…
Ultrafast heat flow in heterostructures of Au nanoclusters on thin-films: atomic-disorder induced by hot electrons
Thomas Vasileiadis, Lutz Waldecker, Dawn Foster +5
We study the ultrafast structural dynamics, in response to electronic excitations, in heterostructures composed of Au nanoclusters on thin-film substrates with the use of f…
Momentum-Resolved View of Electron-Phonon Coupling in Multilayer WSe
Lutz Waldecker, Roman Bertoni, H. Hübener +5
We investigate the interactions of photoexcited carriers with lattice vibrations in thin films of the layered transition metal dichalcogenide (TMDC) WSe. Employing femtosecond…
Coherent and Incoherent Structural Dynamics in Laser-Excited Antimony
Lutz Waldecker, Tobias Zier, Thomas Vasileiadis +5
We investigate the excitation of phonons in photoexcited antimony and demonstrate that the entire electron-lattice interactions, in particular coherent and incoherent electron-phon…
Generation and evolution of spin-, valley- and layer-polarized excited carriers in inversion-symmetric WSe2
Roman Bertoni, Christopher W. Nicholson, Lutz Waldecker +11
Manipulation of spin and valley degrees of freedom is a key step towards realizing novel quantum technologies, for which atomically thin transition metal dichalcogenides (TMDCs) ha…
Electron-phonon coupling and energy flow in a simple metal beyond the two-temperature approximation
Lutz Waldecker, Roman Bertoni, Jan Vorberger +1
The electron-phonon coupling and the corresponding energy exchange was investigated experimentally and by ab initio theory in non-equilibrium states of the free-electron metal alum…
Compact femtosecond electron diffractometer with 100 keV electron bunches approaching the single-electron pulse duration limit
Lutz Waldecker, Roman Bertoni, Ralph Ernstorfer
We present the design and implementation of a highly compact femtosecond electron diffractometer working at electron energies up to 100 keV. We use a multi-body particle tracing co…
Time-Domain Separation of Optical Properties From Structural Transitions in Resonantly Bonded Materials
Lutz Waldecker, Timothy A. Miller, Miquel Rude +6
The extreme electro-optical contrast between crystalline and amorphous states in phase change materials is routinely exploited in optical data storage and future applications inclu…
Experimental Investigation of Plastic Deformations Before Granular Avalanche
Axelle Amon, Roman Bertoni, Jérôme Crassous
We present an experimental study of the deformation inside a granular material that is progressively tilted. We investigate the deformation before the avalanche with a spatially re…