2013/11/01 by M. Barthelemy, Mircea-Vasile Vomir, Barthelemy, M. +15
Engineering · Physics and Astronomy · #FOS: Physical sciences #Magneto-Optical Properties and Applications #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Optical Network Technologies #Optics (physics.optics) #Photonic and Optical Devices #cond-mat.mes-hall #cond-mat.mtrl-sci #physics.optics
paper · pdf · doi:10.48550/arxiv.1311.0080
4 figures, submitted to Phys. Rev. Lett
arxiv created 2013/11/01 · openalex publication_date 2013/11/01 · arxiv updated 2013/11/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report about the dephasing of the spins states in a Garnet film excited by femtosecond laser pulses. It is shown that magneto-optical four-wave-mixing signals are efficiently generated and controlled with an external static magnetic field. The self-diffraction of either two or three femtosecond pulses allows us determining independently the coherent response time (T2 < 50 fs) and the population relaxation, which occurs in several steps. After the laser induced demagnetization, the spin-lattice relaxation is the dominant mechanism (T1,spin-lat < 1.35 ps) and the precession of the magnetization takes place at later times (T1,prec < 150 ps). The coherent response of the spins states is modeled with a multi-level hydrogen-like system, taking into account the fundamental relativistic quantum dynamics of the spins. Our experimental approach is general and opens the way to investigating quantum magnetism in ordered magnetic systems useful for applications in information and communications technologies.