Publications de Serhii Polishchuk

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

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

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

Majed Chergui, Nicola Marzari, Marco Grioni, Nicola Colonna, Michele Puppin, Alberto Crepaldi, 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

Time- and Angle-Resolved Photoelectron Spectroscopy of Solar Materials

Serhii Polishchuk

Natural foundations defining the manner in which a solid material interacts with optical radiation are primarily encoded in the material's momentum-dependent band structure and the microscopic details of the electron-lattice interactions. An access to this ...

EPFL2021

Radial Spin Texture of the Weyl Fermions in Chiral Tellurium

Majed Chergui, Henrik Moodysson Rønnow, Marco Grioni, Oleg Yazyev, Luc Testa, Daniel Gosalbez Martinez, Michele Puppin, Philippe Bugnon, Luca Moreschini, Alberto Crepaldi

Trigonal tellurium, a small-gap semiconductor with pronounced magneto-electric and magneto-optical responses, is among the simplest realizations of a chiral crystal. We have studied by spin- and angle-resolved photoelectron spectroscopy its unconventional ...

AMER PHYSICAL SOC2020

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

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

Light-Induced Renormalization of the Dirac Quasiparticles in the Nodal-Line Semimetal ZrSiSe

Majed Chergui, Marco Grioni, Arnaud Magrez, Michele Puppin, Helmuth Berger, Philippe Bugnon, Luca Moreschini, Alberto Crepaldi, Simon Karl Moser, Gianmarco Gatti

In nodal-line semimetals, linearly dispersing states form Dirac loops in the reciprocal space with a high degree of electron-hole symmetry and a reduced density of states near the Fermi level. The result is reduced electronic screening and enhanced correla ...

2020