2021/11/02 by Fabian Mertens, Mertens, Fabian, David Mönkebüscher +19
Physics and Astronomy · #Mechanical and Optical Resonators #Semiconductor Quantum Structures and Devices #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2111.01464
A coherent THz optical lattice mode is triggered by femtosecond laser pulses\nin the antiferromagnetic van der Waals semiconductor FePS3. The 380 nm thick\nexfoliated flake was placed on a substrate and laser-driven lattice and spin\ndynamics were investigated as a function of the excitation photon energy and\nsample temperature. The pump-probe spectroscopic measurements reveal that the\nphoto-induced phonon is generated by a displacive mechanism. The amplitude of\nthe phononic signal decreases as the sample is heated up to the N 'eel\ntemperature and vanishes as the phase transition to the paramagnetic phase\noccurs. This evidence confirms that the excited lattice mode is intimately\nconnected to the long-range magnetic order. Therefore our work discloses a\npathway towards a femtosecond coherent manipulation of the magneto-crystalline\nanisotropy in a van der Waals antiferromagnet. In fact, it is reported that by\napplying a magnetic field the induced phonon mode hybridizes via the\nKittel-mechanism with zone-centre magnons.\n