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Title: THz-Driven Ultrafast Spin-Lattice Scattering in Amorphous Metallic Ferromagnets

Authors:
; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1297277
Grant/Contract Number:
AC02-76SF00515; 2015-SLAC-100238
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 117; Journal Issue: 8; Related Information: CHORUS Timestamp: 2017-04-05 20:36:03; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Bonetti, S., Hoffmann, M. C., Sher, M. -J., Chen, Z., Yang, S. -H., Samant, M. G., Parkin, S. S. P., and Dürr, H. A.. THz-Driven Ultrafast Spin-Lattice Scattering in Amorphous Metallic Ferromagnets. United States: N. p., 2016. Web. doi:10.1103/PhysRevLett.117.087205.
Bonetti, S., Hoffmann, M. C., Sher, M. -J., Chen, Z., Yang, S. -H., Samant, M. G., Parkin, S. S. P., & Dürr, H. A.. THz-Driven Ultrafast Spin-Lattice Scattering in Amorphous Metallic Ferromagnets. United States. doi:10.1103/PhysRevLett.117.087205.
Bonetti, S., Hoffmann, M. C., Sher, M. -J., Chen, Z., Yang, S. -H., Samant, M. G., Parkin, S. S. P., and Dürr, H. A.. 2016. "THz-Driven Ultrafast Spin-Lattice Scattering in Amorphous Metallic Ferromagnets". United States. doi:10.1103/PhysRevLett.117.087205.
@article{osti_1297277,
title = {THz-Driven Ultrafast Spin-Lattice Scattering in Amorphous Metallic Ferromagnets},
author = {Bonetti, S. and Hoffmann, M. C. and Sher, M. -J. and Chen, Z. and Yang, S. -H. and Samant, M. G. and Parkin, S. S. P. and Dürr, H. A.},
abstractNote = {},
doi = {10.1103/PhysRevLett.117.087205},
journal = {Physical Review Letters},
number = 8,
volume = 117,
place = {United States},
year = 2016,
month = 8
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevLett.117.087205

Citation Metrics:
Cited by: 2works
Citation information provided by
Web of Science

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  • When a laser pulse excites a ferromagnet, its spin undergoes a dramatic change. The initial demagnetization process is very fast. Experimentally, it is found that the demagnetization time is related to the spin moment in the sample. In this study, we employ the first-principles method to directly simulate such a process. We use the fixed spin moment method to change the spin moment in ferromagnetic nickel, and then we employ the Liouville equation to couple the laser pulse to the system. We find that in general the dependence of demagnetization time on the spin moment is nonlinear: It decreases withmore » the spin moment up to a point, after which an increase with the spin moment is observed, followed by a second decrease. To understand this, we employ an extended Heisenberg model, which includes both the exchange interaction and spin-orbit coupling. The model directly links the demagnetization rate to the spin moment itself and demonstrates analytically that the spin relaxes more slowly with a small spin moment. A future experimental test of our predictions is needed.« less
  • Cited by 4
  • Low-angle inelastic-neutron-scattering experiments were performed on an amorphous ferromagnet of composition (Fe/sub 93/Mo/sub 7/)/sub 80/B/sub 10/P/sub 10/ with T/sub c/ = 450 K. Well-defined spin waves were observed over the entire range of momentum transfer for which the scattering triangle could be closed (q < or = 0.25 A/sup -1/). The results were consistent with a normal ferromagnetic dispersion relation h..omega.. (q) = ..delta.. + Dq/sup 2/ + Eq/sup 4/ + ..., where the gap ..delta.. can be largely accounted for by demagnetization effects. Low-temperature magnetization measurements were performed and fit to the relation M (T) = M/sub 0/ (1-BT/supmore » 3///sup 2/-CT/sup 5///sup 2/). The measured long-wavelength spin waves account for only 70% of the density of magnon states necessary to explain M (T). For temperatures below 300 K, the mean spin-wave energies are well represented by the relation <..omega.. (q, T) > = <..omega.. (q, 0) >(1-0.612(T/T/sub c/)/sup 5///sup 2/).« less
  • The electrical resistivity in the amorphous ferromagnets Fe{sub 80}B{sub 20{minus}{ital x}}Si{sub {ital x}} (0{le}{ital x}{le}12) has been measured in the temperature range 8--300 K. We find from a detailed quantitative analysis that over and above a dominant structural contribution there exists in such alloys a significant magnetic contribution proportional to {ital T}{sup 3/2} for {ital T}{much lt}{ital FTHETA}{sub {ital D}} (Debye temperature). No definite conclusion could be reached about the temperature dependence ({ital T}{sup 3/2} or {ital T}{sup 2}) of the magnetic contribution at higher temperatures, viz., {ital T}{ge}{ital FTHETA}{sub {ital D}}. Magnetoresistance data show that the temperature dependence ofmore » the resistivity is not affected in the presence of external magnetic fields. However, the coefficient of the magnetic term shows a small decrease with increasing field at low temperatures but remains constant at high temperatures.« less