Ultrafast Measurements of the Interfacial Spin Seebeck Effect in Au and Rare-Earth Iron Garnet Bilayers

Abstract

We investigate picosecond spin-currents across Au/iron-garnet interfaces in response to ultrafast laser heating of the electrons in the Au film. In the picoseconds after optical heating, interfacial spin currents occur due to an interfacial temperature difference between electrons in the metal and magnons in the insulator. We report measurements of this interfacial longitudinal spin Seebeck effect between Au and rare-earth iron-garnet insulators, i.e. RE${}_3$ Fe${}_5$O${}_{12}$, where RE is Y, Eu, Tb, Tm. We use time domain thermoreflectance (TDTR) measurements to characterize the thermal response of the bilayer to ultrafast optical heating. We use time-resolved magneto-optic Kerr effect (TR-MOKE) measurements of the Au layer to measure the time-evolution of spin accumulation in the Au film. We observe a spin Seebeck effect between Au/TmIG that is three times larger than for an Au/YIG bilayer. The interfacial thermal conductance between electrons in the Au and magnons in the TmIG layer is ~ 3 $\frac{MW}{m^{2}K}$.

References in corpus (17)

• Spin Caloritronics
• Interface-Induced Phenomena in Magnetism
• Tutorial: Time-domain thermoreflectance (TDTR) for thermal property characterization of bulk and thin film materials
• Temperature dependence of spin diffusion length and spin Hall angle in Au and Pt
• Magnon, phonon and electron temperature profiles and the spin Seebeck effect in magnetic insulator/normal metal hybrid structures
• Femtosecond formation dynamics of the spin Seebeck effect revealed by terahertz spectroscopy
• The effect of the magnon dispersion on the longitudinal spin Seebeck effect in yttrium iron garnets (YIG)
• Thermally driven spin and charge currents in thin NiFe2O4/Pt films
• Origin of the thickness-dependent low-temperature enhancement of spin Seebeck effect in YIG films
• Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures
• Observation of huge thermal spin currents in magnetic multilayers
• Picosecond spin Seebeck effect
• Quantum thermodynamics of complex ferrimagnets
• Systematic Control of Strain-Induced Perpendicular Magnetic Anisotropy in Epitaxial Europium and Terbium Iron Garnets Thin Films
• Parametric dependence of hot electron relaxation timescales on electron-electron and electron-phonon interaction strengths
• An integrated approach to doped thin films with strain tunable magnetic anisotropy: Powder synthesis, target preparation and pulsed laser deposition of Bi:YIG
• Spincaloritronic measurements: a round robin comparison of the longitudinal spin Seebeck effect

Cited by in corpus (3)

• Spin Seebeck Effect: Sensitive Probe for Elementary Excitation, Spin Correlation, Transport, Magnetic Order, and Domains in Solids
• First and second order magnetic anisotropy and damping of europium iron garnet under high strain
• Magneto-optical Kerr spectra of gold induced by spin accumulation