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- Unikandanunni, Vivek, et al.
(author)
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Inertial spin dynamics : the role of magneto-crystalline anisotropy
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Other publication (other academic/artistic)abstract
- We investigate the spin dynamics driven by terahertz magnetic fields in epitaxial thin films of cobalt in its three crystalline phases with distinct magneto-crystalline anisotropy. The terahertz magnetic field generates a torque on the magnetization which causes it to precess for about 1 ps, with a sub-picosecond temporal lag from the driving force. Then, the magnetization undergoes natural damped oscillations in the THz range at a characteristic frequency of the crystalline phase, containing higher-order harmonics of the fundamental. We describe the experimental observations solving the inertial Landau-Lifshitz-Gilbert equation. Using the results from the relativistic theory of magnetic inertia, we find that the angular momentum relaxation time η is the only material parameter needed to describe all the experimental evidence. Our experiments suggest a correlation between η and the strength of the magneto-crystalline anisotropy
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2. |
- Unikandanunni, Vivek, 1993-, et al.
(author)
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Inertial Spin Dynamics in Epitaxial Cobalt Films
- 2022
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 129:23
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Journal article (peer-reviewed)abstract
- We investigate the spin dynamics driven by terahertz magnetic fields in epitaxial thin films of cobalt in its three crystalline phases. The terahertz magnetic field generates a torque on the magnetization which causes it to precess for about 1 ps, with a subpicosecond temporal lag from the driving force. Then, the magnetization undergoes natural damped THz oscillations at a frequency characteristic of the crystalline phase. We describe the experimental observations solving the inertial Landau-Lifshitz-Gilbert equation. Using the results from the relativistic theory of magnetic inertia, we find that the angular momentum relaxation time η is the only material parameter needed to describe all the experimental evidence. Our experiments suggest a proportionality between η and the strength of the magnetocrystalline anisotropy.
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