Accessing ultrafast spin-transport dynamics in copper using broadband terahertz spectroscopy

Abstract

We study the spatiotemporal dynamics of ultrafast electron spin transport across nanometer-thick copper layers using broadband terahertz spectroscopy. Our analysis of temporal delays, broadening and attenuation of the spin-current pulse revealed ballistic-like propagation of the pulse peak, approaching the Fermi velocity, and diffusive features including a significant velocity dispersion. A comparison to the frequency-dependent Ficks law identified the diffusion-dominated transport regime for distances larger than 2 nm. The findings lie the groundwork for designing future broadband spintronic devices.

V3: AAM, Licence: CC BY Main text consists of 3 figures and 4 pages of text

References in corpus (11)

• Super-Diffusive Spin-Transport as a Mechanism of Ultrafast Demagnetization
• Time-domain observation of ballistic orbital-angular-momentum currents with giant relaxation length in tungsten
• Spintronic Sources of Ultrashort Terahertz Electromagnetic Pulses
• Contribution of defects to the spin relaxation in copper nanowires
• Laser induced THz emission from femtosecond photocurrents in Co/ZnO/Pt and Co/Cu/Pt multilayers
• Broadband terahertz probes of anisotropic magnetoresistance disentangle extrinsic and intrinsic contributions
• Frequency-independent terahertz anomalous Hall effect in DyCo${}_5$, Co${}_{32}$Fe${}_{68}$ and Gd${}_{27}$Fe${}_{73}$ thin films from DC to 40 THz
• Transition of laser-induced terahertz spin currents from torque- to conduction-electron-mediated transport
• Signal propagation in time-dependent spin transport
• Impact of gigahertz and terahertz transport regimes on spin propagation and conversion in the antiferromagnet IrMn
• Effective exchange interaction for terahertz spin waves in iron layers

Cited by in corpus (3)

• Deciphering the origin of spin current in spintronic terahertz emitters and its imprint on their electromagnetic radiation via time-dependent density functional theory
• Optimizing spin-based terahertz emission from magnetic heterostructures
• Optically induced magnetic inertia and magnons from non-Markovian extension of the Landau-Lifshitz-Gilbert equation