Simulation of Hot-Carrier Dynamics and Terahertz Emission in Laser-Excited Metallic Bilayers
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PhysRevApplied.11.054083.pdf
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AMER PHYSICAL SOCCitation
Nenno, D. M., Binder, R., & Schneider, H. C. (2019). Simulation of Hot-Carrier Dynamics and Terahertz Emission in Laser-Excited Metallic Bilayers. Physical Review Applied, 11(5), 054083.Journal
PHYSICAL REVIEW APPLIEDRights
© 2019 American Physical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present a multiscale model that simulates optically induced spin currents in metallic bilayer structures that emit terahertz radiation after optical pulse excitation. We describe hot-electron transport in a metallic bilayer by a Boltzmann transport equation, which is solved numerically by a particle-in-cell approach. Optical excitation and propagation effects are taken into account by our determining the emitted terahertz waves from the excited-carrier dynamics. We apply this approach to an Fe/Pt bilayer and show in detail how microscopic scattering effects and transport determine the emitted signal. The versatility of the approach presented here allows it to be readily adapted to a wide spectrum of spintronic-terahertz-emitter designs. As an example, we show how the terahertz generation efficiency, defined as the output-power-to-input-power ratio, can be increased and optimized with use of serially stacked layers in conjunction with terahertz antireflective coatings. We derive an analytical expression for the terahertz emission of a single layer that allows us to determine the relationship between the emitted field and the current profile that generates it.ISSN
2331-7019Version
Final published versionSponsors
German Science Foundation [SFB/TRR 173 Spin+X]; Graduate School of Excellence MAINZ (Excellence Initiative) [DFG/GSC 266]; [SFB/TRR 173]ae974a485f413a2113503eed53cd6c53
10.1103/physrevapplied.11.054083