0000000000420206

AUTHOR

S. Dal Conte

showing 2 related works from this author

Laser-driven quantum magnonics and terahertz dynamics of the order parameter in antiferromagnets

2017

The impulsive generation of two-magnon modes in antiferromagnets by femtosecond optical pulses, so-called femto-nanomagnons, leads to coherent longitudinal oscillations of the antiferromagnetic order parameter that cannot be described by a thermodynamic Landau-Lifshitz approach. We argue that this dynamics is triggered as a result of a laser-induced modification of the exchange interaction. In order to describe the oscillations we have formulated a quantum mechanical description in terms of magnon pair operators and coherent states. Such an approach allowed us to} derive an effective macroscopic equation of motion for the temporal evolution of the antiferromagnetic order parameter. An impli…

PhysicsMagnonicsStrongly Correlated Electrons (cond-mat.str-el)Condensed Matter - Mesoscale and Nanoscale PhysicsTerahertz radiationMagnonEquations of motionFOS: Physical sciencesPhysics::Optics02 engineering and technologyQuantum entanglement021001 nanoscience & nanotechnology01 natural sciences3. Good healthCondensed Matter - Strongly Correlated ElectronsQuantum mechanicsPicosecondSpectroscopy of Solids and Interfaces0103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)Condensed Matter::Strongly Correlated Electrons010306 general physics0210 nano-technologyQuantumSpin-½
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Intravalley spin-flip relaxation dynamics in single-layer WS2

2019

Two-dimensional Transition Metal Dichalcogenides (TMDs) have been widely studied because of the peculiar electronic band structure and the strong excitonic effects [1]. In these materials the large spin-orbit coupling lifts the spin degeneracy of the valence (VB) and the conduction band (CB) giving rise to the A and B interband excitonic transitions. In monolayer WS2, the spins of electrons in the lowest CB and in the highest VB at K/K' point of the Brillouin zone are antiparallel resulting in an intravalley dark exciton state at a lower energy than the bright exciton, see left panel of Fig.1. On the one hand, the presence of dark excitons has been revealed indirectly from the observation o…

PhysicsValence (chemistry)Condensed matter physicsSpinsScatteringExciton02 engineering and technologyElectronCondensed Matter::Mesoscopic Systems and Quantum Hall Effect021001 nanoscience & nanotechnology01 natural sciencesBrillouin zoneCondensed Matter::Materials Science0103 physical sciencesSpin-flip010306 general physics0210 nano-technologyElectronic band structure
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