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Alberto Crepaldi

Cette personne a quitté l’EPFL

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Publications associées (38)

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Dynamics of correlation-frozen antinodal quasiparticles in superconducting cuprates

Alberto Crepaldi

Many puzzling properties of high-critical temperature (T-c) superconducting (HTSC) copper oxides have deep roots in the nature of the antinodal quasiparticles, the elementary excitations with wave vector parallel to the Cu-O bonds. These electronic states ...

AMER ASSOC ADVANCEMENT SCIENCE2018

Momentum and photon energy dependence of the circular dichroic photoemission in the bulk Rashba semiconductors BiTeX (X = I, Br, Cl)

Helmuth Berger, Arnaud Magrez, Marco Grioni, Oleg Yazyev, Philippe Bugnon, Alberto Crepaldi, Luca Moreschini, Gabriel Albert Autes, Jens Christian Johannsen, Cédric Tournier-Colletta

Bulk Rashba systems BiTeX (X = I, Br, Cl) are emerging as important candidates for developing spintronics devices because of the coexistence of spin-split bulk and surface states, along with the ambipolar character of the surface charge carriers. The need ...

American Physical Society2014

Bulk diffusive relaxation mechanisms in optically excited topological insulators

Helmuth Berger, Arnaud Magrez, Philippe Bugnon, Alberto Crepaldi

The possibility to inject spin currents in topological insulators (TIs) by ultrashort optical pulses has stimulated intense studies of their out-of-equilibrium electronic properties. However, a comprehensive description of the electronic relaxation dynamic ...

Amer Physical Soc2017

Evidence of Large Polarons in Photoemission Band Mapping of the Perovskite Semiconductor CsPbBr3

Matthias Wolf, Majed Chergui, Nicola Marzari, Marco Grioni, Alberto Crepaldi, Michele Puppin, Nicola Colonna, Gianmarco Gatti, Serhii Polishchuk, Riccardo De Gennaro, Thomas Roland Barillot

Lead-halide perovskite (LHP) semiconductors are emergent optoelectronic materials with outstanding transport properties which are not yet fully understood. We find signatures of large polaron formation in the electronic structure of the inorganic LHP CsPbB ...

AMER PHYSICAL SOC2020

Structural and electronic properties of the Bi/Au(110)-1x4 surface

Harald Brune, Marco Grioni, Oleg Yazyev, François Patthey, Marina Pivetta, Alberto Crepaldi, Gabriel Albert Autes, Cédric Tournier-Colletta

We report on the structural and electronic properties of the Bi/Au(110)-1 x 4 surface, by combining scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and first-principles calculations. The analysis of the precursor 1 x 8 moire struc ...

American Physical Society2013

Diversity of radial spin textures in chiral materials

Oleg Yazyev, Alberto Crepaldi, Daniel Gosalbez Martinez

We introduce a classification of the radial spin textures in momentum space that emerge at the high-symmetry points in crystals characterized by nonpolar chiral point groups (D2, D3, D4, D6, T, O). Based on the symmetry constraints imposed by these point g ...

Amer Physical Soc2023

Tunable Carrier Multiplication and Cooling in Graphene

Marco Grioni, Alberto Crepaldi, Jens Christian Johannsen

Time- and angle-resolved photoemission measurements on two doped graphene samples displaying different doping levels reveal remarkable differences in the ultrafast dynamics of the hot carriers in the Dirac cone. In the more strongly (n-)doped graphene, we ...

Amer Chemical Soc2015

Time-resolved ARPES at LACUS: Band Structure and Ultrafast Electron Dynamics of Solids

Majed Chergui, Helmuth Berger, Arnaud Magrez, Marco Grioni, Frank van Mourik, Alberto Crepaldi, Christopher Alexander Arrell, Philippe Bugnon, Gianmarco Gatti, José Javier Pancracio Ojeda Andara, Silvan Dino Marcos Roth

The manipulation of the electronic properties of solids by light is an exciting goal, which requires knowledge of the electronic structure with energy, momentum and temporal resolution. Time- and angle-resolved photoemission spectroscopy (tr-ARPES) is the ...

2017

Giant Ambipolar Rashba Effect in the Semiconductor BiTeI

Klaus Kern, Helmuth Berger, Marco Grioni, Oleg Yazyev, Philippe Bugnon, Alberto Crepaldi, Luca Moreschini, Gabriel Albert Autes, Simon Karl Moser, Naunidh Singh Virk, Cédric Tournier-Colletta

We observe a giant spin-orbit splitting in the bulk and surface states of the noncentrosymmetric semiconductor BiTeI. We show that the Fermi level can be placed in the valence or in the conduction band by controlling the surface termination. In both cases, ...

Amer Physical Soc2012

Advancing non-equilibrium ARPES experiments by a 9.3 eV coherent ultrafast photon source

Helmuth Berger, Philippe Bugnon, Alberto Crepaldi

The quest for investigating the non-equilibrium dynamics of the band structure of strongly-correlated materials over their entire Brillouin zone is a primary objective. However, the actual ultrafast UV light sources are not suitable for addressing several ...

Elsevier Science Bv2016

Anisotropic spin gaps in BiAg2-Ag/Si(111)

Klaus Kern, Marco Grioni, Alberto Crepaldi, Emmanouil Frantzeskakis

We present a detailed analysis of the band structure of the root 3 x root 3 R 30 degrees BiAg2/Ag/Si(111) trilayer system by means of high resolution Angle Resolved Photoemission Spectroscopy (ARPES). BiAg2/Ag/Si(111) exhibits a complex spin-polarized elec ...

2012

Insight into the electronic structure of semiconducting epsilon-GaSe and epsilon-InSe

Helmuth Berger, Marco Grioni, Alberto Crepaldi

Metal monochalcogenides (MX) have recently been rediscovered as two-dimensional materials with electronic properties highly dependent on the number of layers. Although some intriguing properties appear in the few-layer regime, the carrier mobility of MX co ...

AMER PHYSICAL SOC2020

SmB6 electron-phonon coupling constant from time- and angle-resolved photoelectron spectroscopy

Alberto Crepaldi, Emmanouil Frantzeskakis

SmB6 is a mixed valence Kondo system resulting from the hybridization between localized f electrons and delocalized d electrons. We have investigated its out-of-equilibrium electron dynamics by means of time- and angle-resolved photoelectron spectroscopy. ...

Amer Physical Soc2016

Ultrafast Dynamics of Massive Dirac Fermions in Bilayer Graphene

Marco Grioni, Alberto Crepaldi, Jens Christian Johannsen

Bilayer graphene is a highly promising material for electronic and optoelectronic applications since it is supporting massive Dirac fermions with a tunable band gap. However, no consistent picture of the gap's effect on the optical and transport behavior h ...

American Physical Society2014

Persistence of a surface state arc in the topologically trivial phase of MoTe2

Helmuth Berger, Arnaud Magrez, Oleg Yazyev, Marco Grioni, Philippe Bugnon, Alberto Crepaldi, Gabriel Albert Autes

The prediction of Weyl fermions in the low-temperature noncentrosymmetric 1T' phase of MoTe2 still awaits clear experimental confirmation. Here, we report angle-resolved photoemission (ARPES) data and ab initio calculations that reveal a surface state arc ...

Amer Physical Soc2017

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

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

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

Momentum-Resolved Spin Dynamics of Bulk and Surface Excited States in the Topological Insulator Bi2Se3

Helmuth Berger, Marco Grioni, Philippe Bugnon, Alberto Crepaldi

The prospect of optically inducing and controlling a spin-polarized current in spintronic devices has generated wide interest in the out-of-equilibrium electronic and spin structure of topological insulators. In this Letter we show that only measuring the ...

Amer Physical Soc2015

Evidence for a Strong Topological Insulator Phase in ZrTe5

Helmuth Berger, Arnaud Magrez, Oleg Yazyev, Philippe Bugnon, Alberto Crepaldi, Gabriel Albert Autes, Luca Gragnaniello

The complex electronic properties of ZrTe5 have recently stimulated in-depth investigations that assigned this material to either a topological insulator or a 3D Dirac semimetal phase. Here we report a comprehensive experimental and theoretical study of bo ...

Amer Physical Soc2016

Photocarrier-induced band-gap renormalization and ultrafast charge dynamics in black phosphorus

Majed Chergui, Marco Grioni, Alberto Crepaldi, Michele Puppin, Gianmarco Gatti, Steven Roth

With its tunable band-gap and its unique optical and electronic properties black phosphorus (BP) opens exciting opportunities for optoelectronic nanotechnology. The band-gap extends from the visible to the mid-infrared spectral range, as a function of samp ...

2019

Photoinduced long-lived state in FeSe0.4Te0.6

Alberto Crepaldi

Fe(Sex)Te(1-)x compounds display a rich phase diagram, ranging from the nematicity of FeSe to the (pi, pi) magnetism of FeTe. We focus on FeSe0.4Te0.6, and exploit tr-ARPES to study its ultrafast electron dynamics following photoexcitation by near-infrared ...

ELSEVIER2021