A5024488385- Topological Materials and Phenomena
- Advanced Condensed Matter Physics
- Electronic and Structural Properties of Oxides
- 2D Materials and Applications
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Graphene research and applications
- Semiconductor materials and devices
- Heusler alloys: electronic and magnetic properties
- Perovskite Materials and Applications
- Surface and Thin Film Phenomena
- Rare-earth and actinide compounds
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum and electron transport phenomena
- Quantum, superfluid, helium dynamics
- Physics of Superconductivity and Magnetism
- Advanced Photocatalysis Techniques
- Iron-based superconductors research
- Multiferroics and related materials
- MXene and MAX Phase Materials
- Inorganic Chemistry and Materials
- Magnetic properties of thin films
- Ferroelectric and Piezoelectric Materials
Synchrotron soleil
2023-2025
University of St Andrews
2021-2024
Istituto Officina dei Materiali
2019-2023
AREA Science Park
2017-2022
University of Milan
2017-2022
The Abdus Salam International Centre for Theoretical Physics (ICTP)
2017
Kagome materials have emerged as a setting for emergent electronic phenomena that encompass different aspects of symmetry and topology. It is debated whether the XV$_6$Sn$_6$ kagome family (where X rare earth element), recently discovered bilayer metals, hosts topologically non-trivial ground state resulting from opening spin-orbit coupling gaps. These states would carry finite spin-Berry curvature, topological surface states. Here, we investigate spin structure family. We obtain evidence...
The relation between crystal symmetries, electron correlations, and electronic structure steers the formation of a large array unconventional phases matter, including magneto-electric loop currents chiral magnetism. Detection such hidden orders is major goal in condensed matter physics. However, to date, nonstandard forms magnetism with ordering have been experimentally elusive. Here, we develop theory for symmetry-broken ground states propose methodology based on circularly polarized...
By combining bulk sensitive soft-x-ray angular-resolved photoemission spectroscopy and first-principles calculations we explored the electron states of WTe_{2}, a candidate type-II Weyl semimetal featuring large nonsaturating magnetoresistance. Despite layered geometry suggesting two-dimensional electronic structure, directly observe three-dimensional dispersion. We report band dispersion in reciprocal direction perpendicular to layers, implying that electrons can also travel coherently when...
Abstract Long-range electronic ordering descending from a metallic parent state constitutes rich playground to study the interplay of structural and degrees freedom. In this framework, kagome metals are in most interesting regime where both phonon electronically mediated couplings significant. Several these systems undergo charge density wave transition. However, date, origin main driving force behind order is elusive. Here, we use metal ScV 6 Sn as platform investigate problem, since it...
The transition-metal chalcogenides include some of the most important and ubiquitous families 2D materials. They host an exceptional variety electronic collective states, which can in principle be readily tuned by combining different compounds van der Waals heterostructures. Achieving this, however, presents a significant materials challenge. highest quality heterostructures are usually fabricated stacking layers exfoliated from bulk crystals, - while producing excellent prototype devices is...
Complete photoemission experiments, enabling measurement of the full quantum set photoelectron final state, are in high demand for studying materials and nanostructures whose properties determined by strong electron spin correlations. Here implementation new polarimeter VESPA (Very Efficient Spin Polarization Analysis) at APE-NFFA beamline Elettra is reported, which based on exchange coupling between a ferromagnetic surface reflectometry setup. The system was designed to be integrated with...
We report on epitaxial growth of Bi2Se3 topological insulator thin films by Pulsed Laser Deposition (PLD). X-ray diffraction investigation confirms that with a single (001)-orientation can be obtained several substrates in narrow (i.e., 20 °C) range deposition temperatures and at high pressure 0.1 mbar). However, only grown (001)-Al2O3 show an almost-unique in-plane orientation. In-situ spin-resolved angular resolved photoemission spectroscopy experiments, performed the NFFA-APE facility...
Long-range electronic order descending from a metallic parent state constitutes rich playground to study the intricate interplay of structural and degrees freedom. With dispersive correlation features as multifold topological Dirac-like itinerant states, van-Hove singularities, correlated flat bands, magnetic transitions at low temperature, kagome metals are located in most interesting regime where both phonon electronically mediated couplings significant. Several these systems undergo...
Altermagnets are a novel platform to realize exotic electromagnetic properties distinct from those of conventional ferromagnets and antiferromagnets. We report results micro-focused angle-resolved photoemission spectroscopy (ARPES) on RuO2, which altermagnetic nature has been under fierce debate. have elucidated the band structure (100), (110) (101) surfaces bulk single crystal. found that, irrespective surface orientation, experimental structures obtained by ARPES commonly show...
We investigate the temperature-dependent electronic structure of van der Waals ferromagnet, CrGeTe$_3$. Using angle-resolved photoemission spectroscopy, we identify atomic- and orbital-specific band shifts upon cooling through ${T_\mathrm{C}}$. From these, together with x-ray absorption spectroscopy magnetic circular dichroism measurements, states created by a covalent bond between Te ${5p}$ Cr ${e_g}$ orbitals as primary driver ferromagnetic ordering in this system, while it is ${t_{2g}}$...
Abstract Quantum materials are central for the development of novel functional systems that often based on interface specific phenomena. Fabricating controlled interfaces between quantum requires adopting a flexible growth technique capable to synthesize different within single-run deposition process with high control structure, stoichiometry, and termination. Among various available thin film technologies, pulsed laser (PLD) allows controlling diverse at level single atomic layers. In PLD...
Two-dimensional van der Waals magnetic semiconductors display emergent chemical and physical properties hold promise for novel optical, electronic "few-layers" functionalities. Transition-metal iodides such as CrI3 VI3 are relevant future spintronic applications; however, detailed experimental information on their ground state is lacking often due to challenging environment. By combining X-ray electron spectroscopies first-principles calculations, we report a complete determination of...
Among transition-metal dichalcogenides, mono and few-layers thick ${\mathrm{VSe}}_{2}$ has gained much recent attention following claims of intrinsic room-temperature ferromagnetism in this system, which have nonetheless proved controversial. Here, we address the magnetic chemical properties $\mathrm{Fe}/{\mathrm{VSe}}_{2}$ heterostructure by combining element sensitive x-ray absorption spectroscopy photoemission spectroscopy. Our circular dichroism results confirm findings that both native...
Two-dimensional (2D) metallic states induced by oxygen vacancies (${V}_{O}\mathrm{s}$) at oxide surfaces and interfaces provide opportunities for the development of advanced applications, but ability to control behavior these is still limited. We used angle resolved photoelectron spectroscopy combined with density-functional theory (DFT) study reactivity ${V}_{O}$-induced (001) surface anatase ${\mathrm{TiO}}_{2}$, where both 2D deeper lying in-gap (IGs) are observed. The IG exhibit...
We unravel the interplay of topological properties and layered (anti)ferromagnetic ordering in EuSn2P2, using spin chemical selective electron X-ray spectroscopies supported by first-principle calculations. reveal presence in-plane long-range ferromagnetic order triggering invariants resulting multiple protection Dirac states. provide clear evidence that layer-dependent spin-momentum locking coexists with ferromagnetism this material, a cohabitation promotes EuSn2P2 as prime candidate axion...
We report the study of anatase TiO2(001)-oriented thin films grown by pulsed laser deposition on LaAlO3(001). A combination in situ and ex methods has been used to address both origin Ti3+-localized states their relationship with structural electronic properties surface subsurface. Localized in-gap are analyzed using resonant X-ray photoelectron spectroscopy related Ti3+ configuration, homogeneously distributed over entire film thickness. find that an increase oxygen pressure corresponds...
We present the results of a photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES) study on high quality, epitaxial ${\mathrm{SrNbO}}_{3}$ thin films prepared in situ by pulsed laser deposition (PLD). show that Fermi surface is composed three bands mainly due to ${\mathrm{t}}_{2g}$ orbitals Nb $4d$, analogy with $3d$-based perovskite systems. The bulk band dispersion for conduction valence states obtained density functional theory (DFT) generally...
Our studies evidence an anisotropic magnetic order below $T_N = 32$~K. Susceptibility data in small fields of about 1~T reveal antiferromagnetic (AFM) for $H \perp c$, whereas \parallel c$ the are reminiscent a field-induced ferromagnetic (FM) structure. At low temperatures and field-dependent magnetization AC susceptibility metamagnetic transition at $H^+ 5$~T, which is absent c$. We assign this to from planar cycloidal spin structure fan-like arrangement above $H^+$. A fully FM polarized...
Abstract In half-metallic systems, electronic conduction is mediated by a single spin species, offering enormous potential for spintronic devices. Here, using microscopic-area angle-resolved photoemission, we show that spin-polarised two-dimensional hole gas naturally realised in the polar magnetic semiconductor AgCrSe 2 an intrinsic self-doping at its CrSe -terminated surface. Through comparison with first-principles calculations, unveil striking role of spin-orbit coupling surface gas,...
Abstract The formation and the evolution of electronic metallic states localized at surface, commonly termed 2D electron gas (2DEG), represents a peculiar phenomenon occurring surface interface many transition metal oxides (TMO). Among TMO, titanium dioxide (TiO 2 ), particularly in its anatase polymorph, stands as prototypical system for development novel applications related to renewable energy, devices sensors, where understanding carrier dynamics is utmost importance. In this study,...