0000000000501393

AUTHOR

Fabian Mertens

0000-0002-7877-0107

showing 2 related works from this author

Ultrafast Coherent THz Lattice Dynamics Coupled to Spins in the van der Waals Antiferromagnet FePS3

2022

Coherent THz optical lattice and hybridized phonon–magnon modes are triggered by femtosecond laser pulses in the antiferromagnetic van der Waals semiconductor FePS3. The laser-driven lattice and spin dynamics are investigated in a bulk crystal as well as in a 380 nm-thick exfoliated flake as a function of the excitation photon energy, sample temperature and applied magnetic field. The pump-probe magneto-optical measurements reveal that the amplitude of a coherent phonon mode oscillating at 3.2 THz decreases as the sample is heated up to the Néel temperature. This signal eventually vanishes as the phase transition to the paramagnetic phase occurs, thus revealing its connection to the long-ra…

spintronicsSemiconductorsMechanics of MaterialsMechanical EngineeringGeneral Materials Scienceddc:530antiferromagnets2D materialsphononMaterialsmagnonultrafast pump-probe spectroscopyvan der Waals semiconductors
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Ultrafast amplification and non-linear magneto-elastic coupling of coherent magnon modes in an antiferromagnet

2021

We investigate the role of domain walls in the ultrafast magnon dynamics of an antiferromagnetic NiO single crystal in a pump-probe experiment with variable pump photon energy. Analysing the amplitude of the energy-dependent photo-induced ultrafast spin dynamics, we detect a yet unreported coupling between the material's characteristic THz- and a GHz-magnon modes. We explain this unexpected coupling between two orthogonal eigenstates of the corresponding Hamiltonian by modelling the magneto-elastic interaction between spins in different domains. We find that such interaction, in the non-linear regime, couples the two different magnon modes via the domain walls and it can be optically exploi…

Terahertz radiationFOS: Physical sciencesGeneral Physics and AstronomyPhysics::Optics02 engineering and technologyPhoton energy01 natural sciencesSettore FIS/03 - Fisica della MateriaCondensed Matter::Materials Sciencesymbols.namesakeMesoscale and Nanoscale Physics (cond-mat.mes-hall)0103 physical sciencesAntiferromagnetism010306 general physicsPhysicsCondensed matter physicsSpinsCondensed Matter - Mesoscale and Nanoscale PhysicsCondensed Matter::OtherMagnonResonance021001 nanoscience & nanotechnology3. Good healthCondensed Matter - Other Condensed MatterCoupling (physics)symbolsCondensed Matter::Strongly Correlated Electrons0210 nano-technologyHamiltonian (quantum mechanics)Other Condensed Matter (cond-mat.other)
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