Silvan Roth

Silvan Roth

École Polytechnique Fédérale de Lausanne

H-index: 18

Europe-Switzerland

About Silvan Roth

Silvan Roth, With an exceptional h-index of 18 and a recent h-index of 13 (since 2020), a distinguished researcher at École Polytechnique Fédérale de Lausanne,

His recent articles reflect a diverse array of research interests and contributions to the field:

Hidden bulk and surface effects in the spin polarization of the nodal-line semimetal ZrSiTe

Radial spin texture of the Weyl fermions in chiral tellurium

Light-induced renormalization of the Dirac quasiparticles in the nodal-line semimetal ZrSiSe

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

Dynamics of excited interlayer states in hexagonal boron nitride monolayers

Silvan Roth Information

University

École Polytechnique Fédérale de Lausanne

Position

___

Citations(all)

1061

Citations(since 2020)

537

Cited By

707

hIndex(all)

18

hIndex(since 2020)

13

i10Index(all)

21

i10Index(since 2020)

14

Email

University Profile Page

École Polytechnique Fédérale de Lausanne

Top articles of Silvan Roth

Hidden bulk and surface effects in the spin polarization of the nodal-line semimetal ZrSiTe

Authors

G Gatti,D Gosálbez-Martínez,S Roth,M Fanciulli,M Zacchigna,M Kalläne,K Rossnagel,C Jozwiak,A Bostwick,E Rotenberg,A Magrez,H Berger,I Vobornik,J Fujii,OV Yazyev,M Grioni,A Crepaldi

Journal

Communications Physics

Published Date

2021/3/17

In non-magnetic materials the combination of inversion symmetry breaking (ISB) and spin-orbit coupling (SOC) determines the spin polarization of the band structure. However, a local spin polarization can also arise in centrosymmetric crystals containing ISB subunits. This is namely the case for the nodal-line semimetal ZrSiTe where, by combining spin- and angle-resolved photoelectron spectroscopy with ab initio band structure calculations, we reveal a complex spin polarization. In the bulk, the valence and conduction bands exhibit opposite spin orientations in two spatially separated two-dimensional ZrTe sectors within the unit cell, yielding no net polarization. We also observe spin-polarized surface states that are well separated in energy and momentum from the bulk bands. A layer-by-layer analysis of the spin polarization allows us to unveil the complex evolution of the signal in the bulk states near the surface …

Radial spin texture of the Weyl fermions in chiral tellurium

Authors

G Gatti,D Gosálbez-Martínez,SS Tsirkin,M Fanciulli,M Puppin,S Polishchuk,S Moser,L Testa,E Martino,S Roth,Ph Bugnon,L Moreschini,A Bostwick,C Jozwiak,E Rotenberg,G Di Santo,L Petaccia,I Vobornik,J Fujii,J Wong,D Jariwala,HA Atwater,HM Rønnow,M Chergui,OV Yazyev,M Grioni,A Crepaldi

Journal

Physical review letters

Published Date

2020/11/19

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 electronic structure and unique spin texture. We identify Kramers–Weyl, composite, and accordionlike Weyl fermions, so far only predicted by theory, and show that the spin polarization is parallel to the wave vector along the lines in k space connecting high-symmetry points. Our results clarify the symmetries that enforce such spin texture in a chiral crystal, thus bringing new insight in the formation of a spin vectorial field more complex than the previously proposed hedgehog configuration. Our findings thus pave the way to a classification scheme for these exotic spin textures and their search in chiral crystals.

Light-induced renormalization of the Dirac quasiparticles in the nodal-line semimetal ZrSiSe

Authors

G Gatti,A Crepaldi,M Puppin,N Tancogne-Dejean,L Xian,U De Giovannini,S Roth,S Polishchuk,Ph Bugnon,A Magrez,H Berger,F Frassetto,L Poletto,L Moreschini,S Moser,A Bostwick,Eli Rotenberg,A Rubio,M Chergui,M Grioni

Journal

Physical review letters

Published Date

2020/8/12

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 correlations between Dirac quasiparticles. Here we investigate the electronic structure of ZrSiSe, by combining time-and angle-resolved photoelectron spectroscopy with ab initio density functional theory (DFT) complemented by an extended Hubbard model (DFT+ U+ V) and by time-dependent DFT+ U+ V. We show that electronic correlations are reduced on an ultrashort timescale by optical excitation of high-energy electrons-hole pairs, which transiently screen the Coulomb interaction. Our findings demonstrate an all-optical method for engineering the band structure of a quantum material.

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

Authors

Michele Puppin,Serhii Polishchuk,Nicola Colonna,Alberto Crepaldi,DN Dirin,Olga Nazarenko,Riccardo De Gennaro,Gianmarco Gatti,Silvan Roth,Thomas Barillot,Luca Poletto,Rui Patrick Xian,Laurenz Rettig,Martin Wolf,Ralph Ernstorfer,Maksym V Kovalenko,Nicola Marzari,Marco Grioni,Majed Chergui

Journal

Physical review letters

Published Date

2020/5/20

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 CsPbBr 3 by means of angle-resolved photoelectron spectroscopy. The experimental valence band dispersion shows a hole effective mass of 0.26±0.02 m e, 50% heavier than the bare mass m 0= 0.17 m e predicted by density functional theory. Calculations of the electron-phonon coupling indicate that phonon dressing of the carriers mainly occurs via distortions of the Pb-Br bond with a Fröhlich coupling parameter α= 1.81. A good agreement with our experimental data is obtained within the Feynman polaron model, validating a viable theoretical method to predict the carrier effective mass of LHPs ab initio.

Dynamics of excited interlayer states in hexagonal boron nitride monolayers

Authors

Matthias Hengsberger,D Leuenberger,A Schuler,S Roth,M Muntwiler

Published Date

2020/3/6

Hexagonal boron nitride (h-BN) is the isoelectronic but insulating counterpart of graphene. Like graphene it can easily be grown as high-quality nanotubes or as single layers on metal surfaces. Both materials can be exfoliated or transferred after single-layer growth from suitable substrates onto new surfaces. In view of electronic devices or optical sensors, for instance, the carrier dynamics in the conduction bands determine the device properties. The band edge of the unoccupied band structure of h-BN is dominated by two kinds of states, free-electron-like interlayer or interface states and a flat conduction band valley derived from π⋆-states. The measurement of excited states and excited-state lifetimes in h-BN is the main topic of the present article with a special focus on the dynamics close to the Γ-point. While the π⋆ conduction band minimum is strongly localised at the boron sites, the charge density of free …

See List of Professors in Silvan Roth University(École Polytechnique Fédérale de Lausanne)

Silvan Roth FAQs

What is Silvan Roth's h-index at École Polytechnique Fédérale de Lausanne?

The h-index of Silvan Roth has been 13 since 2020 and 18 in total.

What are Silvan Roth's top articles?

The articles with the titles of

Hidden bulk and surface effects in the spin polarization of the nodal-line semimetal ZrSiTe

Radial spin texture of the Weyl fermions in chiral tellurium

Light-induced renormalization of the Dirac quasiparticles in the nodal-line semimetal ZrSiSe

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

Dynamics of excited interlayer states in hexagonal boron nitride monolayers

are the top articles of Silvan Roth at École Polytechnique Fédérale de Lausanne.

What is Silvan Roth's total number of citations?

Silvan Roth has 1,061 citations in total.

What are the co-authors of Silvan Roth?

The co-authors of Silvan Roth are Marco Grioni, Alberto Crepaldi, Dominik Leuenberger, Michele Puppin, Luca Castiglioni, Dr. Huanyao Cun.

Co-Authors

H-index: 66
Marco Grioni

Marco Grioni

École Polytechnique Fédérale de Lausanne

H-index: 23
Alberto Crepaldi

Alberto Crepaldi

École Polytechnique Fédérale de Lausanne

H-index: 19
Dominik Leuenberger

Dominik Leuenberger

Universität Zürich

H-index: 17
Michele Puppin

Michele Puppin

École Polytechnique Fédérale de Lausanne

H-index: 14
Luca Castiglioni

Luca Castiglioni

Universität Zürich

H-index: 12
Dr. Huanyao Cun

Dr. Huanyao Cun

École Polytechnique Fédérale de Lausanne

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