Theory of laser-induced demagnetization at high temperatures
TLDR
In this article, a self-consistent random phase approximation of the spin system was derived for a broad range of temperature and the dependence of demagnetization on the temperature and pumping laser intensity was calculated in detail.Abstract:
Laser-induced demagnetization is theoretically studied by explicitly taking into account interactions among electrons, spins, and lattice. Assuming that the demagnetization processes take place during the thermalization of the subsystems, the temperature dynamics is given by the energy transfer between the thermalized interacting baths. These energy transfers are accounted for explicitly through electron-magnon and electron-phonon interactions, which govern the demagnetization time scale. By properly treating the spin system in a self-consistent random phase approximation, we derive magnetization dynamic equations for a broad range of temperature. The dependence of demagnetization on the temperature and pumping laser intensity is calculated in detail. In particular, we show several salient features for understanding magnetization dynamics near the Curie temperature. While the critical slowdown in dynamics occurs, we find that an external magnetic field can restore the fast dynamics. We discuss the implication of the fast dynamics in the application of heat-assisted magnetic recording.read more
Citations
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All-Optical Control of Magnetization in Quantum-Confined Ultrathin Magnetic Metals.
TL;DR: In this article, the free electron model was used to derive all-optical control dynamics of magnetization in sub-10 nm metallic thin films with femtosecond laser pulses and showed that the density of states at Fermi level and electron-phonon coupling coefficients (G_ep) in ultrathin metals have very high sensitivity to film thickness within a few Angstroms.
Posted Content
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References
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Journal ArticleDOI
All-optical magnetic recording with circularly polarized light.
C.D. Stanciu,Fredrik Hansteen,Alexey Kimel,Andrei Kirilyuk,Arata Tsukamoto,Akiyoshi Itoh,Theo Rasing +6 more
TL;DR: It is experimentally demonstrate that the magnetization can be reversed in a reproducible manner by a single 40 femtosecond circularly polarized laser pulse, without any applied magnetic field, revealing an ultrafast and efficient pathway for writing magnetic bits at record-breaking speeds.
Journal ArticleDOI
Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer
William Albert Challener,Chubing Peng,Amit Vasant Itagi,Duane Karns,Wei Peng,Yingguo Peng,XiaoMin Yang,Xiaobin Zhu,N. J. Gokemeijer,Y. T. Hsia,Ganping Ju,Robert Earl Rottmayer,Michael Allen Seigler,Edward Charles Gage +13 more
TL;DR: In this article, a near-field transducer with efficient optical energy transfer was used to record a 70-nm track above the Curie point in nanoseconds and record data at an areal density of ∼375 Tb/m−2.