Publications by Michele Puppin

Ultrafast momentum-resolved visualization of the interplay between phonon-mediated scattering and plasmons in graphite

Thomas La Grange, Fabrizio Carbone, Ivan Madan, Francesco Barantani, Michele Puppin, Alexey Sapozhnik

Scattering between charges and collective modes in materials governs phenomena such as electrical resistance, energy dissipation, and phase switching. Studying such scattering requires simultaneous access to ultrafast and momentum-resolved dynamics of sing ...

2025

Light-induced renormalization of the band structure of chiral tellurium

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

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, Giulia Fulvia Mancini, Michele Puppin, Hui-Yuan Chen, Ludmila Maria Diniz Leroy, 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

Magneto-optical response of the magnetic semiconductors EuCd2X2 (X =P, As, Sb)

Ivica Zivkovic, Jan Hugo Dil, Michele Puppin, Fei Guo

In this study, we identify EuCd2X2 (for X = P, As, Sb) as a series of magnetic semiconductors. We examine how the band gap of the series responds to X changing from phosphorus (P), to arsenic (As), and finally antimony (Sb). We characterize the samples usi ...

2024

Separation of kinetic rate orders in extreme ultraviolet transient grating spectroscopy

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

Real-and reciprocal space characterization of the three-dimensional charge density wave in quasi-one-dimensional CuTe

Arnaud Magrez, Jan Hugo Dil, Michele Puppin, Fei Guo

Low-dimensional materials are susceptible to electronic instabilities such as charge density waves (CDWs), originating from a divergence in the Lindhard electron response function, combined with a finite electron-phonon coupling strength. In this paper, we ...

American Physical Society (APS)2024

High-resolution MHz time- and angle-resolved photoemission spectroscopy based on a tunable vacuum ultraviolet source

Marco Grioni, Thomas La Grange, Henrik Moodysson Rønnow, Fabrizio Carbone, Jan Hugo Dil, Michele Puppin, Fei Guo

The time- and angle-resolved photoemission spectroscopy (trARPES) allows for direct mapping of the electronic band structure and its dynamic response on femtosecond timescales. Here, we present a new ARPES system, powered by a new fiber-based femtosecond l ...

Aip Publishing2024

EuCd2As2: A Magnetic Semiconductor

Ivica Zivkovic, Jan Hugo Dil, Michele Puppin, Jian Rui Soh, Fei Guo

EuCd2As2 is now widely accepted as a topological semimetal in which a Weyl phase is induced by an external magnetic field. We challenge this view through firm experimental evidence using a combination of electronic transport, optical spectroscopy, and exci ...

2023

Data for "Ultrafast deep-ultraviolet study of photoexcited aqueous Ferrioxalate"

Majed Chergui, Malte Oppermann, Michele Puppin, Christoph Bostedt, Hui-Yuan Chen

Data repository for the following publication: A. Duque-Prata*, H.-Y. Chen*, L. Müller, M. Oppermann, M. Puppin, C. Serpa, C. Bostedt and M. Chergui, “Ultrafast deep-ultraviolet study of photoexcited aqueous Ferrioxalate”, submitted to ChemPhotoCh ...

Zenodo2023

Atomic-Level Description of Thermal Fluctuations in Inorganic LeadHalide Perovskites

Alfredo Pasquarello, Majed Chergui, Nicola Colonna, Oliviero Cannelli, Michele Puppin, Ludmila Maria Diniz Leroy

A comprehensive microscopic description of thermally induceddistortions in lead halide perovskites is crucial for their realistic applications, yetstill unclear. Here, we quantify the effects of thermal activation in CsPbBr3nanocrystals across length scale ...

AMER CHEMICAL SOC2022

Nanoscale-Resolved Surface-to-Bulk Electron Transport in CsPbBr3 Perovskite

Marco Grioni, Majed Chergui, Alberto Crepaldi, Nicola Marzari, Nicola Colonna, Gianmarco Gatti, Serhii Polishchuk, Michele Puppin

Describing the nanoscale charge carrier transport at surfaces and interfaces is fundamental for designing highperformance optoelectronic devices. To achieve this, we employ time-and angle-resolved photoelectron spectroscopy with ultraviolet pump and extrem ...

AMER CHEMICAL SOC2022

Excited-state band structure mapping

Michele Puppin

Angle-resolved photoelectron spectroscopy is an extremely powerful probe of materials to access the occupied electronic structure with energy and momentum resolution. However, it remains blind to those dynamic states above the Fermi level that determine te ...

2022

Decoupled Structural Responses upon Light and Thermal Functional Activation in CsPbBr3 Perovskites

Alfredo Pasquarello, Majed Chergui, Oliviero Cannelli, Michele Puppin

We combine time-resolved and temperature-dependent X-ray absorption spectroscopy with state-of-the-art first principles simulations to quantify light- and thermally-induced structural distortions in CsPbBr3 perovskite nanocrystals with atomic-level precisi ...

Optica Publishing Group2022

Coherent Modulation of Quasiparticle Scattering Rates in a Photoexcited Charge-Density-Wave System

Michele Puppin

We present a complementary experimental and theoretical investigation of relaxation dynamics in the charge-density-wave (CDW) system TbTe3 after ultrafast optical excitation. Using time- and angleresolved photoemission spectroscopy, we observe an unusual t ...

2022

Optically induced changes in the band structure of the Weyl charge-density-wave compound (TaSe4)(2)I

Helmuth Berger, Marco Grioni, Majed Chergui, Oleg Yazyev, Alberto Crepaldi, Daniel Gosalbez Martinez, Michele Puppin

Collective modes are responsible for the emergence of novel quantum phases in topological materials. In the quasi-one dimensional (1D) Weyl semimetal (TaSe4)(2)I < i , a charge density wave (CDW) opens band gaps at the Weyl points, thus turning the system ...

2022

Quantifying Photoinduced Polaronic Distortions in Inorganic Lead Halide Perovskite Nanocrystals

Majed Chergui, Giulia Fulvia Mancini, Andre Al Haddad, Thomas Charles Henry Rossi, Nicola Colonna, Dominik Kinschel, James Michael Budarz, Oliviero Cannelli, Michele Puppin, Ludmila Maria Diniz Leroy

The development of next-generation perovskite-based optoelectronic devices relies critically on the understanding of the interaction between charge carriers and the polar lattice in out-of-equilibrium conditions. While it has become increasingly evident fo ...

2021

Origin of large magnetoresistance in the topological nonsymmorphic semimetal TaSe3

Jean-Philippe Ansermet, Helmuth Berger, Oleg Yazyev, Alberto Crepaldi, Gabriel Albert Autes, Gianmarco Gatti, Daniel Gosalbez Martinez, Quansheng Wu, Michele Puppin, Shengnan Zhang

TaSe3 is a layered van der Waals semimetal with several inverted band gaps throughout the entire Brillouin zone and nontrivial Z(2) topological indices, which place it at the boundary between a strong and a weak topological phase. Our transport experiments ...

2021

Nonequilibrium charge-density-wave order beyond the thermal limit

Michele Puppin

The interaction of many-body systems with intense light pulses may lead to novel emergent phenomena far from equilibrium. Recent discoveries, such as the optical enhancement of the critical temperature in certain superconductors and the photo-stabilization ...

Nature Research2021

Direct measurement of key exciton properties: Energy, dynamics, and spatial distribution of the wave function

Martin Wolf, Michele Puppin

Excitons, Coulomb-bound electron-hole pairs, are the fundamental excitations governing the optoelectronic properties of semiconductors. Although optical signatures of excitons have been studied extensively, experimental access to the excitonic wave functio ...

Wiley2021

Ultrafast photoelectron spectroscopy of photoexcited aqueous ferrioxalate

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, José Javier Pancracio Ojeda Andara, Luca Longetti, Thomas Roland Barillot, Michele Puppin

The photochemistry of metal-organic compounds in solution is determined by both intra- and inter-molecular relaxation processes after photoexcitation. Understanding its prime mechanisms is crucial to optimise the reactive paths and control their outcome. H ...

2021