Controlling polarization of spintronic THz emitter by remanent magnetization texture

Journal Article · 03 August 2022 · Applied Physics Letters

DOI: https://doi.org/10.1063/5.0096252 · OSTI ID:1879577

Wu, Weipeng; Lendinez, Sergi ; Kaffash, Mojtaba Taghipour ; Schaller, Richard D. ; Wen, Haidan; Jungfleisch, M. Benjamin

Terahertz (THz) sciences and technologies have contributed to a rapid development of a wide range of applications and expanded the frontiers in fundamental science. Spintronic terahertz emitters offer conceptual advantages since the spin orientation in the magnetic layer can be easily controlled either by the externally applied magnetic field or by the internal magnetic field distribution determined by the specific shape of the magnetic elements. Here, we report a switchable terahertz source based on micropatterned magnetic heterostructures driven by femtosecond laser pulses. We show that the precise tunability of the polarization state is facilitated by the underlying magnetization texture of the magnetic layer that is dictated by the shape of the microstructure. These results also reveal the underlying physical mechanisms of a nonuniform magnetization state on the generation of ultrafast spin currents in the magnetic heterostructures. Our findings indicate that the emission of the linearly polarized THz waves can be switched on and off by saturating the sample using a biasing magnetic field, opening fascinating perspectives for integrated on-chip THz devices with wide-ranging potential applications.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1879577
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 5 Vol. 121; ISSN 0003-6951
• Publisher: American Institute of PhysicsCopyright Statement
• Country of Publication: United States
• Language: English