Publications de Marco Grioni | EPFL Graph Search

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The ordered (1 x 2) monolayer of Bi on the InAs(110) surface is studied by means of angle-resolved high-resolution ultra-violet photoemission at room temperature. Four bands of Bi;induced surface states are singled out and their dispersion is mapped along the high-symmetry directions of the surface Brillouin zone. The highest occupied state S' lies inside the InAs(110) energy gap at 0.2 eV binding energy and spreads across the Fermi level, determining the semimetallic character of the system. The second-hig

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 ...

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 ...

Combined optical and photoemission experiments on the quasi-one dimensional Bechgaard salts reveal the non-Fermi liquid character of these prototype quasi-one dimensional interacting electron systems. We show that various aspects of the exotic normal state properties along the chains are consistent with the predictions of the Tomonaga-Luttinger liquid theory. We also discuss the effect of interchain coupling on the insulator-metal transition, associated with the electron confinement-deconfinement crossover.

We demonstrate that the spin-orbit coupling of two-dimensional surface states can be detected locally by scanning-tunneling spectroscopy (STS). The spin splitting of the surface state induces a singularity in the local density of states which can be detect ...

We exploited resonant photoemission at the Ce 4d --> 4f absorption edge to investigate the Ce 4f states in CePd3. High resolution spectra reveal, near the Fermi level, the characteristic fine structure of intermediate valence Ce compounds. The spectral lineshape is consistent with the typical "Kondo" character of CePd, but the prominent (f(0)) ionization peak is found at the unusually low binding energy of 1 eV. We briefly discuss the implications of these observations.

The electronic structure of ex situ grown highly oriented thin films of the quasi-ID organic metal tetrathiafulvalene tetracyanoquinodimethane (TTF-TCNQ) has been characterized by means of temperature-dependent high-resolution angle-resolved photoemission spectroscopy and X-ray photoelectron spectroscopy. Band dispersion near the Fermi level (EF) is observed at low temperatures (similar to 100 K) for as-received samples. At room temperature both charged and neutral TCNQ species (TCNQ(-) and TCNQ(0), respect

Resonant inverse photoemission spectroscopy (RIPES) is a new spectroscopic probe of the electronic states in solids. It exploits the resonant enhancement of the inverse photoemission cross section occurring at appropriate core absorption edges, and is therefore the counterpart of resonant photoemission for the unoccupied states. We present the results of a RIPES investigation of cerium-based Kondo systems, which illustrate the main aspects of the technique, and briefly review some recent developments involv

Recent high-resolution photoemission results on high-T-c superconductors and other low-dimensional systems solve some critical issues but also open new fundamental questions. A recent breakthrough enabled us to clarify the interplay of conflicting periodicities in photoemission data. thus legitimizing the photoemission analysis of crystals with super-periodicities. On the other hand, results on the role of doping and of intentional disorder in Bi2Sr2CaCu2O8+x single crystals raise questions about the origin

High-resolution angle-resolved photoemission data from the insulating phase of the charge-density-wave (CDW) material 1T-TaS2 reveal the backfolding of the electronic bands associated with the CDW superlattice, but also an additional, unexpected periodicit ...

We present a study of the resonant inelastic scattering response of YbInCu4 excited at the tender YbM5 x-ray edge. In the high-temperature, paramagnetic phase, we observe a multiplet structure which can be understood at an ionic level. Upon cooling through ...

We report high resolution angle-scanned photoemission and Fermi surface (FS) mapping experiments on the layered transition-metal dichalcogenide 1T-TaS2 in the quasicommensurate (metallic) and the commensurate (insulating) charge-density-wave (CDW) phase. Instead of a nesting induced partially removed FS in the CDW phase we find a pseudogap over large portions of the FS. This remnant FS exhibits the symmetry of the one-particle normal state FS. Possibly, this Mott localization induced transition represents t

Angle-resolved photoemission (ARPES) on the quasi-one-dimensional conductor (TaSe4)(2)I shows a hidden Fermi-surface crossing in its metallic state and the opening of a Peierls gap at low temperatures, The underlying quasiparticles have vanishing spectral weight and extremely short coherence lengths. They are interpreted as polarons in the strong-coupling adiabatic Lin-Lit, and almost all their ARPES weight is incoherent. These observations suggest a scenario where the long-standing contradictions between A

From a recent calculation of the electronic structure of Ce [Phys. Rev. B 43, 3137 (1991)] Eriksson et al. conclude that the alpha-phase is best described as a delocalized 4f-electron system. We show that the limited experimental evidences provided in support of this statement are not conclusive and do not allow one to discard the single-impurity model, which is consistent with all spectroscopic data.

By combining angle-resolved photoemission spectroscopy and scanning tunneling microscopy we reveal the structural and electronic properties of multilayer graphene on Ru(0001). We prove that large ethylene exposure allows the synthesis of two distinct phase ...

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 ...

We analyzed photoemission data for several doping levels of the Bi2Sr2CaCu2O8+x compounds, ranging from overdoped to underdoped. We show that the high frequency part of the spectra near (0,pi) can be described by Fermi liquid theory in the overdoped regime, but exhibits a non-Fermi liquid behavior in the underdoped regime. We further demonstrate that this behavior fits reasonably well to a 1/root omega behavior suggested for systems with strong spin fluctuations. [S0163-1829(98)50338-4].

Nodal angle-resolved photoemission spectra taken on overdoped La1.77Sr0.23CuO4 are presented and analyzed. It is proven that the low-energy excitations are true Landau Fermi-liquid quasiparticles. We show that momentum and energy distribution curves can be analyzed self-consistently without quantitative knowledge of the bare band dispersion. Finally, by imposing Kramers-Kronig consistency on the self-energy Sigma, insight into the quasiparticle residue is gained. We conclude by comparing our results to quas

We investigated the effect of disorder on the spectral properties of the high temperature superconductor Bi2Sr2CaCu2O8+x. We find that small defect densities, in the low 10(-3) range, already suppress the characteristic spectral signature of the superconducting state, while new excitations appear within the gap. We conclude that, due to defect-induced pair breaking, superconducting pairs and normal carriers coexist below T-c. At higher levels of disorder the normal state is also strongly affected, and the q

We investigated the effects of disorder in Bi2Sr2CaCu2O8+x high temperature superconductor. We found that small defect densities already suppress the characteristic spectral signature of the superconducting state. The spectral line shape clearly reflects new excitations within the gap, as expected for defect-induced pair breaking.

Marco Grioni

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Occupied surface-state bands of the (1 x 2) ordered phase of Bi/InAs(110)

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

Radial Spin Texture of the Weyl Fermions in Chiral Tellurium

Optical and photoemission evidence for a Tomonaga-Luttinger liquid in the Bechgaard salts

Local detection of spin-orbit splitting by scanning tunneling spectroscopy

High-resolution resonant photoemission study of the 4f states in a typical Kondo system: CePd3

Surface characterization of metallic molecular organic thin films: tetrathiafulvalene tetracyanoquinodimethane

Resonant inverse photoemission in 4f systems

High-T-c superconductivity: new issues from photoemission data

Unexpected periodicity in the quasi-two-dimensional Mott insulator 1T-TaS2 revealed by angle-resolved photoemission

Kondo lattice excitation observed using resonant inelastic x-ray scattering at the YbM5 edge

Remnant fermi surface in the presence of an underlying instability in layered 1T-TaS2

Spectroscopic indications of polaronic carriers in the quasi-one-dimensional conductor (TaSe4)(2)I

Surface Electronic-Structure Of Ce In The Alpha-Phase And Gamma-Phase

Two Distinct Phases of Bilayer Graphene Films on Ru(0001)

Consequences of Broken Translational Symmetry in FeSexTe1-x

Evolution of the quasiparticle spectral function in cuprates

Nodal Landau Fermi-liquid quasiparticles in overdoped La1.77Sr0.23CuO4

Spectroscopic signatures of defect-induced pair breaking in Bi2Sr2CaCu2O8+x

Defect-induced changes in the spectral properties of Bi2Sr2CaCu2O8+x: Angle-resolved photoemission study