Publications de Luca Moreschini

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

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

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

Radial Spin Texture of the Weyl Fermions in Chiral Tellurium

Philippe Bugnon, Marco Grioni, Majed Chergui, Oleg Yazyev, Luca Moreschini, Henrik Moodysson Rønnow, Alberto Crepaldi, Simon Karl Moser, Luc Testa, Mauro Fanciulli, Edoardo Martino, Gianmarco Gatti, Daniel Gosalbez Martinez, Silvan Dino Marcos Roth, Serhii Polishchuk, Michele Puppin

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

Volatile two-dimensional electron gas in ultrathin BaTiO3 films

Marco Grioni, Luca Moreschini, Simon Karl Moser, Sara Fatale

We investigate the metallic surface state in ultrathin films of BaTiO3 by angle-resolved photoemission spectroscopy. We find Fermi-surface contours derived from the Ti 3d t(2g) conduction band, similar as in SrTiO3 but with broader spectral features due to ...

AMER PHYSICAL SOC2018

Electronic Phase Separation and Dramatic Inverse Band Renormalization in the Mixed-Valence Cuprate LiCu2O2

Helmuth Berger, Philippe Bugnon, Marco Grioni, Arnaud Magrez, Luca Moreschini, Simon Karl Moser, Gianmarco Gatti

We measured, by angle-resolved photoemission spectroscopy, the electronic structure of LiCu2O2, a mixed-valence cuprate where planes of Cu(I) (3d(10)) ions are sandwiched between layers containing one-dimensional edge-sharing Cu(II) (3d(9)) chains. We find ...

Amer Physical Soc2017

A novel quasi-one-dimensional topological insulator in bismuth iodide beta-Bi4I4

László Forró, Marco Grioni, Oleg Yazyev, Luca Moreschini, Gabriel Albert Autes, Jens Christian Johannsen, Andrea Pisoni, Wentao Zhang

Recent progress in the field of topological states of matter(1,2) has largely been initiated by the discovery of bismuth and antimony chalcogenide bulk topological insulators (TIs; refs 3-6), followed by closely related ternary compounds(7-16) and predicti ...

Nature Publishing Group2016

Nature and topology of the low-energy states in ZrTe5

Helmuth Berger, Marco Grioni, Luca Moreschini, Jens Christian Johannsen

Long known for its peculiar resistivity, showing a thus far unexplained anomalous peak as a function of temperature, ZrTe5 has recently received rising attention in a somewhat different context. While both theoretical and experimental results seem to point ...

Amer Physical Soc2016

Bulk and surface band structure of the new family of semiconductors BiTeX (X=I, Br, Cl)

Helmuth Berger, Philippe Bugnon, Marco Grioni, Arnaud Magrez, Oleg Yazyev, Luca Moreschini, Alberto Crepaldi, Simon Karl Moser, Gabriel Albert Autes, Jens Christian Johannsen

We present an overview of the new family of semiconductors BiTeX (X = I, Br, Cl) from the perspective of angle resolved photoemission spectroscopy. The strong band bending occurring at the surface potentially endows them with a large flexibility, as they a ...

Elsevier2015

Angle-Resolved Photoemission Spectroscopy of Tetragonal CuO: Evidence for Intralayer Coupling Between Cupratelike Sublattices

Marco Grioni, Frédéric Mila, Luca Moreschini, Simon Karl Moser, Hongyu Yang, Davide Innocenti

We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as m ...

2014

Consequences of Broken Translational Symmetry in FeSexTe1-x

Marco Grioni, Luca Moreschini, Ping-Hui Lin, Davide Innocenti

We investigate the consequences of broken translational symmetry in the superconductor FeSexTe1-x using angle-resolved photoemission spectroscopy. We find that the intensity does not follow the periodicity dictated by the crystal structure, owing to the fo ...

Amer Physical Soc2014

Lithographic patterning of insulating or semiconducting solid state material in crystalline form

Luca Moreschini, Simon Karl Moser

A method for lithographic patterning of an insulating or semiconducting solid state material in crystalline form, said method comprising a step where said material is exposed to an amount of radiation which is sufficient to change its insulating or semicon ...

2014

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

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

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

Tunable Polaronic Conduction in Anatase TiO2

Helmuth Berger, László Forró, Marco Grioni, Arnaud Magrez, Luca Moreschini, Jacim Jacimovic, Simon Karl Moser

Oxygen vacancies created in anatase TiO2 by UV photons (80–130 eV) provide an effective electron-doping mechanism and induce a hitherto unobserved dispersive metallic state. Angle resolved photoemission reveals that the quasiparticles are large polarons. T ...

Amer Physical Soc2013

Electronic Instability in a Zero-Gap Semiconductor: The Charge-DensityWave in (TaSe4)(2)I

Helmuth Berger, Marco Grioni, Oleg Yazyev, Luca Moreschini, Alberto Crepaldi, Simon Karl Moser, Gabriel Albert Autes, Cédric Tournier-Colletta

We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in t ...

American Physical Society2013

Giant Ambipolar Rashba Effect in the Semiconductor BiTeI

Helmuth Berger, Philippe Bugnon, Klaus Kern, Marco Grioni, Oleg Yazyev, Luca Moreschini, Alberto Crepaldi, Simon Karl Moser, Gabriel Albert Autes, 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

Electronic structure of single crystal UPd3, UGe2, and USb2 from hard X-ray and angle-resolved photoelectron spectroscopy

Marco Grioni, Luca Moreschini

Electronic structure of single crystal UPd3, UGe2, and USb2 has been measured from hard X-ray photoelectron spectroscopy (HAXPES) with 7.6 keV photons at the European Synchrotron Radiation Facility (ESRF). Lower photon energy angle-resolved photoelectron s ...

Elsevier2011

Assessing the atomic contribution to the Rashba spin-orbit splitting in surface alloys: Sb/Ag(111)

Klaus Kern, Marco Grioni, Christian Reinhard Ast, Luca Moreschini

We have studied the electronic structure of the Ag(111)(root 3x root 3)R30 degrees-Sb surface alloy by angle-resolved photoemission. We find two hybrid surface bands, similar to the isostructural Ag(111)-Bi interface. The spin-orbit coupling induced spin s ...

2009

Spin-orbit coupling effects in the band structure of surface alloys

Luca Moreschini

At the surface of a solid, quantum mechanics allows the existence of two-dimensional Bloch waves as solutions of the Schrödinger equation. These "surface" states are interesting both for fundamental and practical reasons, and have been extensively explored ...

EPFL2009

Origin and manipulation of the Rashba splitting in surface alloys

Marco Grioni, Luca Moreschini

A novel method is demonstrated to tailor the electronic structure of high-Z surface alloys showing a giant Rashba splitting by means of electron doping. This aims for new model systems to study unconvential spin topologies and for possible applications in ...

Open Science2009

Influence of the substrate on the spin-orbit splitting in surface alloys on (111) noble-metal surfaces

Klaus Kern, Marco Grioni, Christian Reinhard Ast, Luca Moreschini

We have studied by angle-resolved photoelectron spectroscopy the ordered XCu2 surface alloys formed by X=Sb and Bi on a Cu(111) substrate. We found clear analogies with the corresponding XAg2 alloys formed by the same elements on Ag(111). The electronic st ...

2009

A time-of-flight-Mott apparatus for soft x-ray spin resolved photoemission on solid samples

Luca Moreschini

We describe a new spectrometer for spin resolved photoemission from solids in the soft x-ray energy range. It is mounted on the ID08 beamline at the ESRF light source and consists of a time-of-flight (TOF) energy analyzer coupled to a retarding mini-Mott s ...

American Institute of Physics2008