Laser induced THz emission from femtosecond photocurrents in Co/ZnO/Pt and Co/Cu/Pt multilayers

Abstract

The ultrashort laser excitation of Co/Pt magnetic heterostructures can effectively generate spin and charge currents at the interfaces between magnetic and nonmagnetic layers. The direction of these photocurrents can be controlled by the helicity of the circularly polarized laser light and an external magnetic field. Here, we employ THz time-domain spectroscopy to investigate further the role of interfaces in these photo-galvanic phenomena. In particular, the effects of either Cu or ZnO interlayers on the photocurrents in Co/X/Pt (X = Cu, ZnO) have been studied by varying the thickness of the interlayers up to 5 nm. The results are discussed in terms of spin-diffusion phenomena and interfacial spin-orbit torque.

arXiv comment15 pages, 6 figures, 2 tables

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Cited by in corpus (14)

• Spintronic Sources of Ultrashort Terahertz Electromagnetic Pulses
• Principles of spintronic THz emitters
• THz emission from Co/Pt bilayers with varied roughness, crystal structure, and interface intermixing
• Modification of spintronic terahertz emitter performance through defect engineering
• Transition of laser-induced terahertz spin currents from torque- to conduction-electron-mediated transport
• THz pulses from optically excited Fe, Pt and Ta based Spintronic Heterostructures
• Impact of gigahertz and terahertz transport regimes on spin propagation and conversion in the antiferromagnet IrMn
• Accessing ultrafast spin-transport dynamics in copper using broadband terahertz spectroscopy
• Laser-induced ultrafast transport and demagnetization at the earliest time: First-principles and real-time investigation
• Different spin relaxation property observed in linearly and circularly polarized laser induced terahertz emission from Bi/Co bilayer
• Harmonic generation predominantly from a single spin channel in a half metal
• Spin injection characteristics of Py/graphene/Pt by gigahertz and terahertz magnetization dynamics driven by femtosecond laser pulse
• Enhancement of Spintronic Terahertz Emission via Annealing in Ferromagnetic Heterostructures
• Femtosecond control of terahertz spin-charge conversion in ferromagnetic heterostructures