Direct detection of magnon spin transport by the inverse spin Hall effect

Abstract

Conversion of traveling magnons into an electron carried spin current is demonstrated in a time resolved experiment using a spatially separated inductive spin-wave source and an inverse spin Hall effect (ISHE) detector. A short spin-wave packet is excited in a yttrium-iron garnet (YIG) waveguide by a microwave signal and is detected at a distance of 3 mm by an attached Pt layer as a delayed ISHE voltage pulse. The delay in the detection appears due to the finite spin-wave group velocity and proves the magnon spin transport. The experiment suggests utilization of spin waves for the information transfer over macroscopic distances in spintronic devices and circuits.

Traveling surface spin-wave resonance spectroscopy using surface acoustic waves

“…Here we extend these initial results to show that the SAW-based excitation of traveling surface spin waves provides a sensitive spectroscopic technique for making quantitative measurements of anisotropic contributions to the spin-wave dispersion and damping. Unlike spin-wave measurement techniques which possess no wavevector selectivity (e.g, anomalous Nernst effect 23 , and spin-pumping [24][25][26] /inverse spin Hall effect detection schemes 1,[27][28][29] ), a SAW can excite a single traveling surface spin wave mode with a definite in-plane wave vector q that is matched to the wave vector chosen for the SAW. While other acoustical techniques (e.g., bulk opto-acoustical techniques) for spin-wave spectroscopy can be used to spectrally select and measure single spin-wave modes, these techniques suffer 3 from the difficulty that quantitative analysis of the spin-wave amplitude line-shapes and spinwave resonance frequencies can be very challenging 30 -a difficulty that we will show SAWbased traveling surface spin-wave spectroscopy does not share.…”

Comparative measurements of inverse spin Hall effects and magnetoresistance in YIG/Pt and YIG/Ta

“…This effect depends on the relative orientation between magnetization and current direction, and has recently been called spin Hall magnetoresistance (SMR) 8 . Experimental studies on spin pumping induced inverse spin Hall voltages (V ISH ) in FM|NM bilayers were first carried out with Pt as NM in combination with NiFe as FM 5,[9][10][11][12] and more recently with the insulating ferrimagnet Yttrium Iron Garnet (YIG) 6,[13][14][15][16][17] . Although other strong spin-orbit metals have been tried in combination with the metallic ferromagnets NiFe 18,19 and CoFeB 20,21 , inverse spin Hall voltage 6,17 and magnetoresistance 8,22 measurements made on YIG|NM have so far been limited to NM=Pt.…”

Spin injection and detection via the anomalous spin Hall effect of a ferromagnetic metal

“…This type of spin current generation perpendicular to a charge current has a significant technological relevance for spin transfer torque devices [3,4] and also for the electrical injection of magnons (quantized spin waves) in magnetic insulators [5][6][7]. The electrical injection and detection of magnons offer a distinct technological advantage for the integration of magnon spintronics into solid state devices, over other magnon generation mechanisms such as spin pumping by radiofrequency fields [8] or the spin Seebeck effect due to a temperature gradient [9]. In this regard Platinum (Pt), a normal metal with a large spin-orbit coupling, is the most commonly used material for the electrical generation (and detection) of magnons via SHE.…”