A5068678035- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- Graphene research and applications
- Topological Materials and Phenomena
- Spectroscopy and Laser Applications
- Electron and X-Ray Spectroscopy Techniques
- Quantum, superfluid, helium dynamics
- Advanced Condensed Matter Physics
- Molecular Spectroscopy and Structure
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- 2D Materials and Applications
- Semiconductor materials and devices
- Atmospheric Ozone and Climate
- Electronic and Structural Properties of Oxides
- Semiconductor materials and interfaces
- Cold Atom Physics and Bose-Einstein Condensates
- Spectroscopy and Quantum Chemical Studies
- Heusler alloys: electronic and magnetic properties
- Molecular Junctions and Nanostructures
- Atomic and Molecular Physics
- Fullerene Chemistry and Applications
- Chemical and Physical Properties of Materials
- Atomic and Subatomic Physics Research
Lund University
2016-2025
MAX IV Laboratory
2016-2025
Leibniz Institute for Solid State and Materials Research
2024
KTH Royal Institute of Technology
2010-2024
Czech Academy of Sciences, Institute of Physics
2024
Chinese Academy of Sciences
2024
Stockholm University
2024
Bhabha Atomic Research Centre
1999-2013
Saha Institute of Nuclear Physics
2011
Uppsala University
2010
Homogeneous large-area graphene monolayers were successfully prepared ex situ on $6H$-SiC(0001). The samples have been studied systematically and the results are compared with those from a sample cut same wafer by in heating. formation of smaller flakes was found sample, which is line earlier observations. Distinctly different observed layers thicknesses, proposed as guideline for determining growth. Recorded $\text{C}\text{ }1s$ spectra consisted three components: bulk SiC, $(G)$, interface...
The long theorized two-dimensional allotrope of SiC has remained elusive amid the exploration graphenelike honeycomb structured monolayers. It is anticipated to possess a large direct band gap (2.5 eV), ambient stability, and chemical versatility. While sp^{2} bonding between silicon carbon energetically favorable, only disordered nanoflakes have been reported date. Here we demonstrate large-area, bottom-up synthesis monocrystalline, epitaxial monolayer atop ultrathin transition metal...
The discovery of van der Waals (vdW) magnets opened a new paradigm for condensed matter physics and spintronic technologies. However, the operations active devices with vdW ferromagnets are limited to cryogenic temperatures, inhibiting their broader practical applications. Here, robust room-temperature operation lateral spin-valve using itinerant ferromagnet Fe5 GeTe2 in heterostructures graphene is demonstrated. properties measured at interface negative spin polarization. Lateral...
The line shape of the photoelectron spectrum emitted from sp-derived surface state at \ensuremath{\Gamma}\ifmmode\bar\else\textasciimacron\fi{} on Cu(111) is investigated. Lorentzian, and temperature dependence width linear, varying 30 meV K to 75 625 K. Less than 5-meV variation with binding energy observed. explained as phonon contribution inverse hole lifetime, predicted be 2\ensuremath{\pi}\ensuremath{\lambda}${\mathit{k}}_{\mathit{bT}}$ allowing determination that electron-phonon mass...
Metallic transition-metal dichalcogenides (TMDCs) are benchmark systems for studying and controlling intertwined electronic orders in solids, with superconductivity developing from a charge-density wave state. The interplay between such phases is thought to play critical role the unconventional of cuprates, Fe-based heavy-fermion systems, yet even more moderately-correlated TMDCs, their nature origins have proved controversial. Here, we study prototypical example, 2H-NbSe2, by spin-...
Complex structure in photoemission spectra of Be(0001) surface states near the Fermi energy is observed and explained as effect strong electron-phonon coupling. The weak momentum dependence contribution to electron self \ensuremath{\Sigma} exploited determine by direct inversion spectra.
We study the nature of $(001)$ surface states in Pb${}_{0.73}$Sn${}_{0.27}$Se newly discovered topological-crystalline-insulator (TCI) phase as well corresponding topologically trivial state above band-gap-inversion temperature. Our calculations predict not only metallic with a nontrivial chiral spin structure for TCI case, but also nonmetallic (gapped) nonzero polarization when system is normal insulator. For both phases, angle- and spin-resolved photoelectron spectroscopy measurements...
We present angle-resolved photoemission spectroscopy measurements of the surface states on in-situ grown (111) oriented films Pb${}_{1\ensuremath{-}x}$Sn${}_{x}$Se, a three-dimensional topological crystalline insulator. observe with Dirac-like dispersion at $\overline{\ensuremath{\Gamma}}$ and $\overline{M}$ in Brillouin zone, supporting recent theoretical predictions for this family materials. study parallel isotropy Dirac-point binding energy states, perform tight-binding calculations to...
The recent discovery of a topological phase transition in IV-VI narrow-gap semiconductors has revitalized the decades-old interest bulk band inversion occurring these materials. Here we systematically study (001) surface states ${\text{Pb}}_{1\ensuremath{-}x}{\text{Sn}}_{x}\text{Se}$ mixed crystals by means angle-resolved photoelectron spectroscopy parameter space $0\ensuremath{\le}x\ensuremath{\le}0.37$ and...
The discovery of topological insulators (TIs), materials with bulk band gaps and protected cross-gap surface states, in compounds such as Bi2Se3 has generated much interest identifying states (TSSs) other classes materials. In particular, recent theory calculations suggest that TSSs may be found half-Heusler ternary compounds. If experimentally realizable, this would provide a platform for entirely new heterostructure spintronic devices make use the structurally-identical but...
Abstract The ability to define an off state in logic electronics is the key ingredient that impossible fulfill using a conventional pristine graphene layer, due absence of electronic bandgap. For years, this property has been missing element for incorporating into next-generation field effect transistors. In work, we grow high-quality armchair nanoribbons on sidewalls 6H-SiC mesa structures. Angle-resolved photoelectron spectroscopy (ARPES) and scanning tunneling measurements reveal...
Abstract Condensed matter physics has often provided a platform for investigating the interplay between particles and fields in cases that have not been observed high-energy physics. Here, using angle-resolved photoemission spectroscopy, we provide an example of this by visualizing electronic structure noncentrosymmetric magnetic Weyl semimetal candidate NdAlSi both paramagnetic ferrimagnetic states. We observe surface Fermi arcs bulk fermion dispersion as well emergence new fermions state....
The electron-phonon coupling parameter ${\ensuremath{\lambda}}_{s}$ at the Be(0001) surface is measured using angle-resolved photoemission and found to be $1.15\ifmmode\pm\else\textpm\fi{}0.1,$ more than four times bulk Be value ${\ensuremath{\lambda}}_{b}=0.24.$ This large for may imply existence of an unusual form superconductivity with a correspondingly transition temperature.
Angle-resolved photoemission shows that the $\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ and $3\ifmmode\times\else\texttimes\fi{}3$ surfaces have almost identical surface band structures with two dispersive bands, one of which crosses Fermi level. The close resemblance between electronic strongly points to a common atomic structure is further supported by Sn $4d$ core-level components observed for both surfaces. existence state bands on calls reevaluation ${T}_{4}$ model Sn/Ge(111)...
Materials with a kagome lattice structure display wealth of intriguing magnetic properties due to their geometric frustration and intrinsically flat band structure. Recently, topological superconducting states have also been observed in systems. The may host ``breathing'' mode that leads charge density wave (CDW) states, if there is strong electron-phonon coupling, electron-electron interaction, or external excitation the material. This can give rise candidate distortions such as star David...
Abstract Recently, a new magnetic phase called altermagnetism has been proposed, ushering in third distinct beyond ferromagnetism and antiferromagnetism. It is expected that this groundbreaking exhibits unique physical properties such as C-paired spin-valley locking, anomalous Hall effect, nontrivial Berry phase, giant magnetoresistance. Among all the predicted candidates, several room temperature altermagnets are suggested to host significant potential applications. Nevertheless, direct...
Photoemission from highly oriented pyrolytic graphite reveals two C $1s$ components separated in binding energy by 120 meV. The high binding-energy component is ascribed to atoms the outermost atomic layer and other deeper layers. interpretation based on low relative intensity observed for line at photon energies chosen such that excitation beneath surface suppressed a bulk band gap of final state. emission line, which dominates, slightly asymmetric has Lorentzian width 160 meV (full half maximum).