0000000000524064

AUTHOR

Michele Puppin

showing 2 related works from this author

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

2020

In nodal-line semimetals linearly dispersing states form Dirac loops in the reciprocal space, with high degree of electron-hole symmetry and almost-vanishing 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). 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 interac…

General PhysicsHubbard modelDirac (software)General Physics and AstronomyFOS: Physical sciencesElectronic structurespin01 natural sciencesMathematical SciencesSettore FIS/03 - Fisica Della Materiasymbols.namesakeCondensed Matter - Strongly Correlated ElectronsEngineeringTDDFT0103 physical sciences010306 general physicsElectronic band structurePhysicsCondensed Matter - Materials ScienceCondensed matter physicsStrongly Correlated Electrons (cond-mat.str-el)Fermi levelMaterials Science (cond-mat.mtrl-sci)dynamicsARPESPhysical SciencesQuasiparticleDensity of statessymbols1st-principlesDensity functional theory
researchProduct

Generation and Evolution of Spin-, Valley-, and Layer-Polarized Excited Carriers in Inversion-Symmetric WSe2

2016

We report the spin-selective optical excitation of carriers in inversion-symmetric bulk samples of the transition metal dichalcogenide (TMDC) ${\mathrm{WSe}}_{2}$. Employing time- and angle-resolved photoelectron spectroscopy (trARPES) and complementary time-dependent density functional theory (TDDFT), we observe spin-, valley-, and layer-polarized excited state populations upon excitation with circularly polarized pump pulses, followed by ultrafast ($l100\text{ }\text{ }\mathrm{fs}$) scattering of carriers towards the global minimum of the conduction band. TDDFT reveals the character of the conduction band, into which electrons are initially excited, to be two-dimensional and localized wit…

PhysicsCondensed matter physicsSpintronicsScatteringGeneral Physics and AstronomyHeterojunction02 engineering and technologyTime-dependent density functional theoryElectron021001 nanoscience & nanotechnology01 natural sciencesExcited state0103 physical sciencesDensity functional theory010306 general physics0210 nano-technologyExcitationPhysical Review Letters
researchProduct