Directional excitation of a high-density magnon gas using coherently driven spin waves
| Autor: | Brecht G. Simon, Hans van den Berg, Samer Kurdi, Allard J. Katan, Iacopo Bertelli, Joris J. Carmiggelt, Toeno van der Sar, Nick de Jong, Helena La, Maximilian Ruf |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Letter
Nitrogen-vacancy centers Magnetometer FOS: Physical sciences Bioengineering Electron Spin relaxometry law.invention law Spin wave Mesoscale and Nanoscale Physics (cond-mat.mes-hall) General Materials Science Spin-½ Physics Condensed matter physics Spins Condensed Matter - Mesoscale and Nanoscale Physics Scattering Mechanical Engineering Magnon General Chemistry Condensed Matter Physics Magnon gas Scanning-probe magnetometry Condensed Matter::Strongly Correlated Electrons Excitation Spin waves Yttrium iron garnet |
| Zdroj: | Nano Letters: a journal dedicated to nanoscience and nanotechnology, 21(19) Nano Letters, 21(19), 8213-8219. AMER CHEMICAL SOC Nano Letters |
| ISSN: | 1530-6984 |
| Popis: | Controlling magnon densities in magnetic materials enables driving spin transport in magnonic devices. We demonstrate the creation of large, out-of-equilibrium magnon densities in a thin-film magnetic insulator via microwave excitation of coherent spin waves and subsequent multimagnon scattering. We image both the coherent spin waves and the resulting incoherent magnon gas using scanning-probe magnetometry based on electron spins in diamond. We find that the gas extends unidirectionally over hundreds of micrometers from the excitation stripline. Surprisingly, the gas density far exceeds that expected for a boson system following a Bose-Einstein distribution with a maximum value of the chemical potential. We characterize the momentum distribution of the gas by measuring the nanoscale spatial decay of the magnetic stray fields. Our results show that driving coherent spin waves leads to a strong out-of-equilibrium occupation of the spin-wave band, opening new possibilities for controlling spin transport and magnetic dynamics in target directions. |
| Databáze: | OpenAIRE |
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