Laser-induced terahertz spin transport in magnetic nanostructures arises from the same force as ultrafast demagnetization
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10453833" target="_blank" >RIV/00216208:11320/22:10453833 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=kHjmQZ.Kui" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=kHjmQZ.Kui</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1103/PhysRevB.106.144427" target="_blank" >10.1103/PhysRevB.106.144427</a>
Alternative languages
Result language
angličtina
Original language name
Laser-induced terahertz spin transport in magnetic nanostructures arises from the same force as ultrafast demagnetization
Original language description
Laser-induced terahertz spin transport (TST) and ultrafast demagnetization (UDM) are central but so far disconnected phenomena in femtomagnetism and terahertz spintronics. Here, we use broadband terahertz emission spectroscopy to reliably measure both processes in one setup. We find that the rate of UDM in a single simple ferromagnetic metal film F such as Co70Fe30 or Ni80Fe20 has the same time evolution as TST from F into an adjacent normal-metal layer N such as Pt or W. As this remarkable agreement refers to two very different samples, an F layer vs an F|N stack, it does not result from the trivial fact that TST out of F reduces the F magnetization at the same rate. Instead, our observation strongly suggests that UDM in F and TST in F|N are driven by the same force, which is fully determined by the state of the ferromagnet. An analytical model quantitatively explains our measurements and reveals that both UDM in the F sample and TST in the associated F|N stack arise from a generalized spin voltage, i.e., an excess of magnetization, which is defined for arbitrary, nonthermal electron distributions. We also conclude that contributions due to a possible temperature difference between F and N, i.e., the spin-dependent Seebeck effect, and optical intersite spin transfer are minor in our experiment. Based on these findings, one can apply the vast knowledge of UDM to TST to significantly increase spin-current amplitudes and, thus, open promising pathways toward energy-efficient ultrafast spintronic devices.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Review B
ISSN
2469-9950
e-ISSN
2469-9969
Volume of the periodical
106
Issue of the periodical within the volume
14
Country of publishing house
US - UNITED STATES
Number of pages
22
Pages from-to
144427
UT code for WoS article
000878594200002
EID of the result in the Scopus database
2-s2.0-85141498409