The discovery of new materials that efficiently transmit spin currents has been important for spintronics and material science1-5. The electric insulator Gd3Ga5O12 (GGG) is a superior substrate for growing magnetic films6, but has never been considered as a conduit for spin currents. Here we report spin current propagation in paramagnetic GGG over several microns. Surprisingly, the spin transport persists up to temperatures of 100 K >> Tg = 180 mK, GGG’s magnetic glass-like transition temperature7. At 5 K we find a spin diffusion length λGGG = 1.8 ± 0.2 µm and a spin conductivity σGGG = (7.3 ± 0.3) × 104 Sm-1 that is larger than that of the record quality magnet Y3Fe5O12 (YIG). We conclude that exchange coupling is not required for efficient spin transport, which challenges conventional models and provides new material-design strategies for spintronic devices.
|Publication status||Published - 2018 Nov 29|
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